Hot Rodding the 5.0 L03

"They thought that it would be a disgrace to go forth as a group. Each entered the forest at a point that he himself had chosen, where it was darkest and there was no path. If there is a path it is someone else's path and you are not on the adventure." - Joseph Campbell, "The Hero's Journey"

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How to get the most out of your 5.0 liter L03 TBI fed V8
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In order to do this, we have to dispel a few myths about the 5.0 TBI small block Chevy engines.

Why is the small block Chevy 5.0 liter TBI engine so maligned by 3rdGen owners? Simple. It doesn't make as much power, from the factory, as the TPI 5.0 liter engine. Is that all? That's all. The carburetor fed LG4 never made that kind of power, but people always point out how 'easy' it is to modify the LG4. Why do people shun the TBI in favor of the TPI or carb setup? It is a very weak argument. But why is that? Both of the EFI fed engines are topped by sophisticated computer controlled EFI systems! Why don't they make the same power? Is it because they are different approaches to the same application?

There are several reasons for this power discrepancy, but they are classic and respond to honest, tried and true hot rodding modifications. If you put out a little money, a little effort, and a little thought into it, the L03 really, really shines. It is one of the easier motors to work on and modify to ever come from GM.

Let's start with the basics. This will be old hat to some of you, brand new knowledge to many others. I really hope that you are learning something here, that's the only reason that I wrote this. Any engine, regardless of induction system, is basically an air pump. The more air you pump through your engine, the more fuel you will burn, and the more power you will produce. The components of the engine, from the plastic air scoop at the front of the wire and paper air cleaner intake tube located on the front radiator support to the very tip of the chrome exhaust pipe, either enhance or retard this pump's ability to produce power. Every single, last, individual component.

Think of your vacuum cleaner at home. It makes a wonderful sound when you fire it up, doesn't it. And the air blowing out the exhaust port is free flowing, isn't it? Well, what happens when you put the vacuum cleaner to the floor, or get something caught in the vacuum tube that restricts the intake charge? You notice a change in power and in exhaust flow, don't you. The engine works harder to overcome the blockage or the extra load, but it's not breathing as well now, and it's not as efficient at its job. Cover up the vacuum cleaner's exhaust and you'll notice another similar difference. Loss of power. The same thing can be said of your car's engine. It's all just plain physics. Your engine is an air pump, pure and simple, and you want to keep the velocity of air through your engine a constant, high velocity, with the least amount of restrictions possible anywhere in the system.

If you have a large free flowing exhausts but a highly restrictive air cleaner assembly, you are not going to get the full use of your exhausts, because your pump will never flow enough air (breathe properly) in order to produce enough exhaust to fill and utilize your large exhausts. Think of this example as trying to run the Boston Marathon and all you can do is breathe through your mouth, through a soda straw stuck between your pursed lips. That's the only way you can breathe. Now, take off and run as fast as you can, for as long as you can, breathing only through that soda straw.

If you have a large free flowing air filtration system leading to your induction system and tiny exhausts or a restricted exhaust system, your engine will never be able to fully utilize the added breathing capability. It will be 'constipated' by the tiny exhaust system, unable to evacuate it's cylinders fast enough to benefit from the increased intake advantage. You've got potential, but another part of your performance train is keeping you from realizing this potential power.

I like to think of engines in the same way that physicists think of energy. You have two types of energy; potential, and kinetic. Potential energy is what can be, like a rock on top of a hill. It's motionless, for now, but it can start rolling down the hill at any moment. Kinetic energy is what power you are making right now, like when the rock starts rolling, it will have a lot of kinetic energy. It's potential will have been converted into kinetic, or actual energy. Potentially, it just sits there, but potentially it can do a lot more. Kinetically it is doing something, it is living up to it's full potential.

I like to think of engines as having potential power and kinetic power. A particular engine might have a lot of potential power but very little kinetic power. You need to shift this balance as much as you can to an engine with very little potential power and a whole bunch of kinetic power.

This philosophy holds true with the L03. It is a engine full of potential power yet possessing very little kinetic power. This is *not* a bad thing, it's a good thing! Potential power, just waiting to become kinetic, and that's the name of the whole hot rodding experience, finding out how to go faster with the odd stuff, or the stuff you are stuck with.

So, your engine is basically a air pump, with a ratio of potential power and kinetic power. You must also realize that every component in an engine must work as one. All individual pieces must be greater in sum than their individual worth. It's a common mistake to think that adding one component to an engine will instantly produce a tire rolling, rubber boiling street romping monster. The uninitiated often drop in a huge cam or a 1000cfm carburetor and then wonder why their ride falls flat on its face.

Bigger is not always better! Put a 1000cfm throttle body on a stock TPI system and the motor takes a nose dive. If you are going to play the high performance game, then the major rule is unity, followed by careful thought, and only through individual parts unity (chosen with a lot of careful thought) can you ever hope to move your engine from a potential power maker to a kinetic power monster.

Truly powerful motors are a marriage of fully complimentary parts, all working in unison, all 'tuned' to compliment each others capabilities. All parts are researched and chosen with but one goal in mind, harmonious, united kinetic power production. An engine is like an orchestra, it's made up of wind, brass, percussion, and a whole range of other complimentary sections, all working to make that beautiful music that we call 'performance'. You know that an orchestra works together to make beautiful music, the same with your engine. You also know what an orchestra sounds like when it is not trained in harmony, when individual sections overlap, or sound louder than other sections, or are out of tune with the piece being played. So, to, are the individual parts of your motor.

Another misconception that I want to clear up right now is horsepower vs. torque. In my book, I don't care how much horsepower that you have, I want to know how much torque you're producing. Horsepower is another poser sign, anyone who brags about how much horsepower they are producing is a sure fire poser and a good bet that they really don't have a clue to what makes engines work or run.

The real performance gurus know that horsepower is simply the efficiency of the engine making torque over a period of time. Torque is the twisting, plant your fanny back in the seat, feeling that you get when the hammer falls. That's torque, not horsepower! The power you feel when you accelerate, when you drop the hammer, that's torque, not horsepower.

Torque. Remember that word, it is the single most important word in high performance. Torque is more important than anything else, the more torque you can make, the lower down in the power band you can make that torque, and the broader the torque curve you can generate (making the most torque over the longest range of the RPM band) is the only thing you really have to be concerned about when building your motor and choosing your parts.

In a otherwise identical car, take two bone stock, identical color, options, etc. '89 Camaro RS's and put in two 305 engines. In one RS, the engine is tuned for horsepower, let's say it makes 300 horses and 200 ft/lbs. of torque. In the other RS, we have a engine tuned for torque. Let's say it makes 200 horsepower and 300 ft/lbs. of torque. Guess which one is going to be faster ...? Right. The 200 horsepower, 300 ft/lbs. torque car will run away from the 300 horsepower / 200 ft/lb. car all day long, without effort.

Face it, the only real difference between a LG4 powered F-body and the L03 powered F-body lies in what is sitting on top of the motor, the only real difference is the type of induction system. Other than the form of induction, that being either carb or TBI, they are both 305s, in F-bodies, and respond to the same basic mods to go faster. Once you realize that the ONLY difference between a 305 LG4 powered '87 Formula and a 305 L03 powered '88 Formula is the highly restrictive intake manifold and the Rochester Model 220 TBI unit, you are fast on a road to realizing that most of the hoopla behind TBI being 'bad' is just total nonsense.

The amount of people I've met on the internet who bad mouth TBI and the 305 is astounding. The ignorance associated with these people and directed towards anyone who asks any questions about TBI or the 305 is equally amazing. I've put what limited knowledge I have here of the 305 (a motor I like VERY much) and TBI (an induction system I like VERY much) here for others to gain what they might can. If you have any information to add, or you find anything here to be in error, please let me know. I will add what is missing and correct what is wrong. With that aside, let's get on with working with your 5.0 liter (non-TPI) motor. If you have TPI in your car, you might learn something here but there are many sites out there dedicated to singing the praises of TPI. This site is not one of them.

Can you modify the L03 to be a strong performer? Yes, it is possible to modify the L03 to be a high performance engine. In fact, it's cheaper to modify the L03 5.0 liter TBI engine than it is to modify a LB9 5.0 liter TPI engine! Let's modify a typical L03 for some serious performance, and on a budget as well. We'll take my car, a '90 Pontiac Formula Firebird, as the project car, and proceed from there. The installation of the parts that I address should be pretty straight forward whether you own a Firebird or a Camaro, base model, Formula, or RS. You might have to modify your plans slightly depending on what model car you have (Firebird, RS, etc.), but all of these mods, with a few exceptions, should work the same regardless of year or model. As long as you have an L03 between your front fenders. If you are interested in what the L03 can become, keep reading!

The first question is why keep the electronic fuel injection system when "everyone" says that a carb is better, easier, and more powerful? I refer this common question to a professional that I respect, Dave Emanuel. I would like to quote him now, from his book, "Small Block Chevy Performance", when he lays out the reasons why you should keep your EFI and not switch out to a carb.

"Electronic fuel injection easily does things that a carburetor and intake manifold could never do, no matter how much they are modified. EFI represents the best method of achieving maximum performance while keeping exhaust emissions as low as possible and fuel economy as high as possible. While the myriad of electrical, computerized components of EFI may seem intimidating, this really isn't so. While certainly more sophisticated than a Holley four barrel, it still performs the same basic function- mixing the fuel and air. These systems are intimidating at first because they're so different. But after working with one for a short time, you'll find that most of the same rules apply."

I couldn't have said it better myself. Ever since EFI first became OEM on high performance cars, I've been fascinated with the aspect of electronic fuel injection in general and throttle body injection in particular. The 1982 L83 5.7 liter Cross-Fire Injection motor on the Corvette and its smaller cousin, the 5.0 liter LU5 Cross Fire Injection motor on the 3rdGen F-body being my first remembrance of GM factory high performance (for that time) EFI. But TBI has always been attractive, because it seemed to be a combination of the best of both worlds, efficiency of EFI, ease of a carb, and superior throttle response as well as improved gas mileage.

Now, as for why we go with TBI over TPI, well TBI has a more open 'mind' than TPI. TBI is a jack of all trades EFI where TPI is a specialist. TBI is also very forgiving, but the farther you push it, the less it forgives, until you reach a limit where TBI simply cannot adapt itself to accommodate your performance needs any longer.

As Patrick Swayze said in "Roadhouse", the movie; "I want you to be nice. I want you to be nice until it is time not to be nice." TBI has that very same attitude. I've said that 400cid is about the limit for the stock TBI, and that seems to have enough room to play around with, but let's look at it from a different point of view. If 400 cubes is the upper limit of adaptability for the 5.0 TBI, then 350 cubes should be well within the safety zone. Now if we set 350 cubes as our new 'upper' limit, we have a lot we can tweak when we begin to play around with an extra 45 cubes. This should be the realm where TBI really starts to scream.

If you've been going step by step, then take a second to review your progress so far. We've come a loooong way, haven't we from that $1500 project car with the worn out suspension and odds and ends that were killing performance? Yes, we have! Now we need to address another problem with the L03, or with any carb / TBI fed 3rdGen F-body; namely that of cold air induction to the carb / injector units.

If the exhaust was criminally restrictive on the 5.0 liter base motors, the second set of criminal charges should be filed against those engineers who designed the air cleaner for the L03. Cold air induction (and its close sibling, ram air induction) have been part of hot rodding since the first amateur welded a open mail box on their hood and called it a 'scoop' (true story, talk about grass roots!). Cold air induction works on the simple principle of colder air is denser, and a denser charge of air burns more gas, more gas makes more power, so the colder the air you can feed your motor, the more power you will make. Ram air induction is, by its very nature, also cold air induction, however, cold air induction is not always ram air induction. Ram air works on the principle of funneling the incoming air into dedicated ducts or pickups that does not allow the air to escape. As the pressure builds, a cheap, natural 'supercharging' effect occurs, resulting in a denser charge the faster the vehicle goes. The faster the vehicle goes, the more air is 'rammed' into the air pickup and it has no where to go except into the motor. For every 10 degrees drop of charge air temperature change (Fahrenheit), you can gain a 1% power increase to total engine output. Drop the inlet intake air temperature going to your carb or TBI unit by 50 degrees F, you pick up 5% power. 5% is 5hp on a 100hp motor, 10hp on a 200hp motor, 15hp on a 300hp motor, 20hp on a 400hp motor, see where we are going? Raising the temperature of the charge decreases the output accordingly. Ram air adds its own natural effect due to the force of the air being rammed into the intake system, enhancing the basic cold air effect for even more performance.

The upside of this is that cold air is free, and is a self replenishing resource. The down side is designing an effective cold air or ram air induction system can be tricky and sometimes costly.

While we're on the subject of gasping for air, that is another MAJOR problem with the LG4 and the L03 engines from the factory; the restrictive air intake system. The stock air cleaner assembly wouldn't flow enough for a healthy four cylinder, let alone a power horse fuelie V8. So, the first problem that must be addressed when it comes to motor on mods is how to get more air to the almost asphyxiated motor, and the colder / denser the air charge the better. Ramming it down the throats of the carb / TBI unit isn't a bad idea either. Remember, your engine is an air pump, and this engine is definitely breathing through a soda straw!

Did you know that the L03 air cleaner, stock, is the same air cleaner as the 5.0 L69 H.O. air cleaner as found on the Pontiac Trans-Am? Strange! But the L69 in the T/A had one advantage going for it that you can add. Keep reading. Most people will tell you to go out and bolt on the dual snorkel air cleaner assembly from the L69 5.0 H.O. engine from the Z28. Yes, that will 'fit', but it also won't fit. Physically, the TBI unit will accept the dual snorkel air cleaner, but if you have the AIR smog equipment on the right side of the engine, near the air cleaner, you know, the little black box with all the hoses going into it, then the air cleaner won't fit.

The much coveted 'dual snorkel' L69 air cleaner is available from NextGenParts and other sources like GM Performance Parts, but it is VERY expensive. It is also available (complete parts / kit) from GM performance, IIRC. You can also find this part at junkyards (occasionally) and at swap meets, on the Internet, etc. Sometimes they command a steep price, don't pay lots of money for a rusty old unit, your money would be better spent going with a little more change for a brand new one. Reconditioning a used dual snorkel isn't hard if you have basic skills and some patience. The most expensive part of this package is, of course, the dual snorkel base and the lid. The associated plastic air scoops and air hoses are comparatively cheap (about $60 for the associate parts). I've found lower dual snorkel bases and lids for as cheap as $25 at a local junk yard, so a careful eye can get you one of these cheap. Another benefit of the dual snorkel is that it works just fine with the Pontiac L69 cold air induction system detailed below. Use the dual snorkel lower base, the Pontiac upper lid, and the other component parts for a truly effective factory OEM style cold air induction system.

At first thought of the restrictive air cleaner assembly, you might think to use one of those aftermarket chrome open element air cleaner units you find at all the parts houses. So, do we use a open element air filter? They are cheap, you can get one at any parts store, but are they worth it? An open element, while increasing the amount of air into the engine and solving one problem, creates another problem entirely, that of hot air intake charging. An open element air filter, while freeing up the breathing, invites your engine to suck hot underhood air and you know that an increase in the temperature of the intake charge will cause you to lose power! While you are getting more air to your motor, you are getting more HOT air to your motor. The temperature of the air you are taking in may very well overcome any advantage you have of the freed up breathing. The factory put the snorkel, the breather tube, and that plastic air scoop at the front of your vehicle for a reason. Cooler air than what could be had under the hood. Have you ever popped your hood on a hot summer day, after running in traffic with the air conditioning going? Did you lose your eyebrows and small facial hair when the heat wave rolled out from under the hood? Imagine your engine having to breathe that! It's not pretty, is it. Now try to breathe that through pursed lips and a soda straw.

What do you do? OEM, aftermarket, custom design your own, put together a hybrid from OEM parts? While it really is up to your own tastes and budget, the overall efficiency of your design has to be ultimately questioned. The end goal of this whole plan is to get as much cold air to your carburetor / TBI unit as you can in the simplest, cheapest, and most effective manner possible. That is the ONLY goal.

Ram air works fine in its dual nature of being both faster moving air and a cooler charge, but on a Formula, you're kind of limited unless you change to the aftermarket ram air hood. ASCD makes a good looking hood for Firebirds, but it is along the lines of forward facing scoops (like the '69 TA, the early 2ndGen Formulas, and the new 4thGen cars) and will require some fabrication to make functional (IIRC). Still, it is a good unit and a quality unit at that, if a bit expensive. For the Camaros, I would try a traditional cowl induction hood which also does not imply any true ram air function. You can plumb this off and draw cold air from the base of the windshield like the 1stGen Camaro SS and Z28s did. Harwood makes a quality aftermarket cowl induction hood in a variety of sizes (2", 3" rise, etc.).

A company called Air Inlet Systems produces a product called "The Ram Air Box". This product is a larger dual snorkel (aftermarket design) drop in air filter design with twin hoses for cold air induction. Getting the hoses past all of the factory emissions plumbing may pose a problem, but the gains are there, and it is cheaper than a factory dual snorkel, if not as good looking. The "Ram Air Box" is highly reminiscent of the early '70's Oldsmobile Cutlass 442 ram air setups made famous by Dr. Oldsmobile and his infamous "W" machines.

If Chevrolet had their own special air cleaner setup for the L69, what did Pontiac ever have? Well, from 1982 to 1984, Pontiac had their own version of a factory cold air induction system based on the power bulge hood, detailed below, so they were ahead of the game by a full year (1982) as the L69 debuted in 1983.

Factory Pontiac power bulge hood cold air induction system- If you own a Firebird, Formula, or Trans-Am with the 5.0 liter LG4 or L03 engine, you can use Pontiac's factory cold air induction system, if you can find one. The system has been discontinued through the dealer and parts catalog, so the junkyard / individual / internet are your only bets. This was standard on the '82 through '84 T/As and it worked quite well. A boundary layer, call it a cushion, of cold air is created, at speed, at the base of the windshield, near the cowl. This is a dense, cold air packet ripe for plumbing. The factory scoop extends into this 'sweet spot' at the base of your windshield and when activated, lets this cold dense air be drawn directly into the intake manifold. This same 'cushion' was the basis for cold air induction into the shaker hood scoops of the early '70's Trans-Ams. The fact that the system looks (and is) overly complex for a 'direct charge' of air is obvious. The fact that the cold air is fed in through a modified air cleaner lid through a fist sized hole is another drawback.

Of course, you'll need the Formula / Trans-Am hood (found on stock '82 through '84 T/As, and on '87 to '92 Formulas, yes, it is the same hood), and all the components (basically the scoop assembly which bolts right into the non-functional hood, and the air cleaner assembly). You should also get the rear grille assembly to prevent small curious children and low flying birds from being sucked into your motor. Although the grille might offer some air flow impedance, it is nothing like the impedance found on the wire mesh of the MAF on TPI cars, and it keeps posers from sticking unwanted things down your scoop when your car is parked in the parking lot.

A good idea would be to scrap the whole vacuum controlled solenoid activator and run a in-line fuse, rocker switch to the scoop assembly and control the opening of the scoop from the interior of your car, much like the ram air setup was controlled on older Trans-Ams and GTOs. Flick the switch on, the scoop opens, flick the switch off, the scoop shuts. Simple. You can shut it in bad weather, open it in good weather. I would mount the rocker switch in the same 'bank' of the console that the rear remote hatch release is. You have a good six inches of free space here, so why not add the scoop control, electric fan control, etc. here. It looks professional. When you install it, make sure that the wires look professionally done.

The stock air cleaner for the '82 through '84 carb fed T/As (not the LU5 Crossfire Injection equipped motors) was not of a higher capacity than the stock L03 air cleaner! They are the SAME! Yeah, go figure. However... When you switch out the twin lid setup, be sure that you run the proper air filter like a reusable K&N model. Also, I would recommend using the K&N X-Stream filter lid in place of the sublid assembly. To find out how to do this modification in detail, follow this link. How to and pics as well, and a few charts.

One idea I have is to just lop off the air cleaner snorkel entirely, sealing the air cleaner completely and letting it breathe *only* through the hood scoop. This would require some cutting, welding, and the fabrication of a pretty trick air cleaner, but it can be done. I'm still wrestling with the merits of this idea, so if you want to run with it, be my guest, and let me know your results. Since this is how the original '67 302 powered Z-28s breathed, I can understand the process and the application. The stock cold air system breathes a lot cooler air than the snorkel and scoop setup, and the intake charge has less distance to travel.

One idea I've been hitting around with was to enlarge the cowl scoop opening, to match it to the air cleaner. Radiusing out the air scoop to match the opening on the air cleaner lid assembly looks like a gain in about 50% more air flow from the scoop to the air filter, not 50% more air flow to the engine, but 50% more air flow coming through the scoop, which any bit helps, but this should help a lot! It's a simple, worthwhile modification to radius out the feed opening from the scoop to the air cleaner assembly. If you look at where the gasket fits, you see that you can widen the lip of the opening in the scoop by possibly as much as an extra inch!

Another idea I'm kicking around is a NACA (National Advisory Council on Aeronautics, what NASA 'used' to be) style duct for the power bulge hood, very similar to that found on the 350 SS fourth Gen cars (which is really just a non-functional hood scoop from a '78-'79 Z28 now made functional. I beat GM to this idea over 15 years ago... on my '78) and such cars as the early '70's AAR series of Plymouth Barracudas. Using the power bulge hood and some reworked ducting, we route high speed, cool air directly into the air cleaner assembly at speed. Instant power increase. Here is what I envision a '91 Formula with a NACA duct modified power bulge hood to look like.

Again, you can make this setup work with critical success by designing a good air cleaner assembly. If you want a forward facing ram air system, just cut out your existing hood like shown below. I *like* the power bulge hood. Do what you want, but please realize, when it comes to getting more and colder air to your engine, the power bulge hood is amazingly adaptive all by itself. Don't throw away something good that you have free just because you haven't explored all the possibilities of it's use!

The 3rdGen F-body (which we will from here on out assume that I am talking about) has a very restrictive air intake tract. The Camaros are bad, but the Firebirds are worse. The cleaner aerodynamics of the 'Bird lend to a very scarce cold air tract. This has been solved by many different approaches by many different people.

There is an excellent source of cold air not ten inches away from your air cleaners' snorkel and almost directly in front of it. That source is the driver's side fender well.

I would use PVC or some other form of 'rigid' plumbing to create a air tube from the new larger air cleaner to a opening inside the fender well, outside of the hot air circulating around the engine compartment, and the ability to breathe much easier (make sure that the rigid tube is of sufficient diameter) through a much cooler source. This method has been done on several different cars. The last of the Ford Mustang GTs with the carb fed 302 HO's had a dual snorkel air cleaner that was plumbed to each fender well for cold air, so this idea isn't new. It is tried, and it does work.

Also, since your engine torques to the right, away from the driver's side fender well, there is a need to use a rigid and flexible connection. The fender well intake should be a large diameter rigid tube, connected in a straight line by a flexible, large diameter tube. If you go rigid all the way, you'll destroy the tube (and possibly other parts connected) the first time you nail it and the engine torques to the right, tearing the rigid tube away from its mount.

The latest incarnation of this idea is to use two surplus (junkyard) air cleaners, each with the approximate size and shape snorkel as found on the HO motor dual snorkel air cleaners. I plan on lopping off my dinky snorkel on the L03's stock air cleaner, lopping off one of the other snorkels, doing a little welding transplant surgery, and voila! I've just increased the intake area of my snorkel by at least 100%, the same idea used by the L69 HO dual snorkel air cleaners on the Z28s.

Solve the L03's air intake restrictions by using a larger air cleaner, flowing cold, fresh air to a low restriction K&N filter (matched to the air cleaner assembly), and a functional factory or aftermarket cold air induction system. It's easier to do than it sounds, it all pretty much bolts up in place, and you might even be able to improve on the design.

Also, don't be mystified if your car doesn't gain a performance advantage right away. The CPU is somewhat of a slow learner. It may take a few days for the CPU to adjust to the new, fresh, cold air charge, and to reprogram itself. Many people have complained about their ram air or fresh air setups not really being worthwhile, only to notice several days later that the car suddenly felt a lot stronger. Even the computer has to take it slow, and in small steps.

So, with fresh, cold air feeding the engine, we should see a massive improvement in performance, right? Yes and no. I know you are going to get tired of this answer, but it's one you are going to have to get used to. We're only going to see an incremental increase in performance, but only because we have tuned only one section of the orchestra. We've only got one section of the orchestra sounding right, we've still got to get the other sections sounding right, and then all sections sounding right together! We're not finished yet, not by a long shot! Don't get frustrated. Little steps lead to a long journey, and the L03 is the perfect candidate for a buildup.

Keeping your engine cool is a critical factor to making horsepower. You need to change out the factory issued 195 degree thermostat for a 165 degree or 165 degree thermostat. This change is fairly easy with only one, very important stipulation. Current hear-say goes that if you lower your thermostat temp, you should change out your computer chip. Your CPU is designed to run at 195 degree engine temperature and it's programming is geared around this. Once you drop the temp via thermostat, your PROM may become hopelessly confused and cause you all sorts of problems. I have done this already, and noticed no problems, but a definite improved performance feel to the motor. Again, you are on your own here. Because my car didn't act up is no guarantee yours won't!

Lowering your engine temperature keeps the engine cooler, generates more horsepower, reduces underhood temperatures, is easier on any underhood electronics, and could require that you change out your stock computer chip, which isn't a bad idea after all. You can do this one simple modification by spending about $120 (get the Hypertech Thermomaster chip), and a good quality thermostat. You'll notice the difference here, because the factory chip is kind of lame when it comes to performance. Most computer chips are cookie cutter and will give you some basic performance improvement, but to make any really improvements would require you to get a custom programmed PROM chip. SUPERCHIPS will custom burn you a PROM based on YOUR modifications. I like this idea. Once you have your motor assembled and all parts in place, it would pay for you to get a custom PROM chip burned, based on YOUR modifications and YOUR engine improvements. Once this is installed, you'll really see some power increases because your computer will have all the data required to function well with your new high performance parts.

A higher capacity aluminum water pump will be lighter and will keep your engine cooler. Losing more pounds and increasing your cooling capacity are two benefits to this mod. Edelbrock makes an excellent Performer series aluminum water pump but you can also get pumps from Flow-Kooler and other aftermarket companies. Increased cooling capacity is almost required for any serious horsepower generating. Make sure that your radiator is up to the challenge of a high performance engine. If a few runs down the track cause your radiator to start overheating, it is time to invest in a larger capacity, higher efficiency radiator. Many companies make these and they are readily available through any parts houses or performance parts catalogs. While you have the cooling system down for modification, now would be a good time to check and change out your coolant for fresh coolant and to make sure that your radiator is up to the capacity. Does it need to be boiled out? If so, do it now, while everything is disconnected. Better now than later. If you managed to switch out to a high capacity aluminum radiator, be sure that you use the correct anti-freeze for it. Some anti-freeze mixtures are not very kind to aluminum radiators!

Several companies offer high capacity light weight aluminum radiators with much higher cooling capacity than the stock unit. A three row unit is preferable to a two row radiator. 'Economy' three row radiators might also be available at your local parts houses. A check of prices on a high capacity radiator by BE COOL industries showed a price tag of nearly $600! The 3 row radiator that my friend bought at Autozone for his Camaro cost considerably less and performed very well.

The addition of a second, aftermarket, high capacity fan might not be a bad idea either. Mount this on the front of the radiator, and have it blow 'into' the radiator, while your factory unit is 'pulling through' the radiator. You'll get more air flow than you ever need. Hook this up to either the factory fan (easy) or to a auxiliary fan switch and turn it on manually. For a high performance street car, I would recommend two fans, especially if you keep your air conditioning. Having a manual toggle switch for your factory fan isn't a bad idea either, and if you go with the auxiliary fan, I would wire it into your factory fan (both come on at the same time) and also have a manual override switch that brings both fans screaming to life when you really need them.

While on the subject of keeping cool, an engine oil cooler of proper capacity is mandatory. These came standard on the 350 TPI engines, so you know that the factory believes in them. Cooler engine oil will keep internal temperatures down, generate more power capacity, and lengthen the service life of your rotating parts. The small block Chevy can also benefit from using a larger capacity oil filter. There are three types of oil filters for a small block Chevy; small, medium, and large. Each is the same filter, just taller. You get increased filtration and also an extra quart or so capacity just by running a larger filter. Check for ground clearance. It's very uncool to put on a new larger capacity filter and then tear it off on the first speed bump you hit leaving a long inky black trail behind you as your engine destroys itself! A high volume oil pump would not be a bad idea, it would be easy to install, and a windage tray might also be a wise investment depending on how you plan to use your car; straight away or auto cross. For auto-cross applications, I would say a windage / baffle design is almost a necessity.

Synthetic oil at the very least would be my recommendation. Synthetics, once very expensive, are now only a little more expensive than regular oil and provide better protection. Oil is the blood of your motor, think of it that way. You wouldn't want hot blood or dirty blood flowing through your heart, would you? No. And your motor doesn't like it either.

So, now we've directed more and colder fresh air to the TBI unit, we've added a larger, lighter, better ported aluminum intake manifold, we've switched out the thermostat and computer chip, and we've handled the cooling chores. We're setting up this engine for a major wakeup.

Talk about cheap? How about this next mod? GM saw fit to seal your hood to the engine compartment and thus deprive that L03 of the ability to get rid of underhood heat and high temperature. On the 2ndGen cars, on the Trans-Ams, side fender extractor vents helped to stabilize the underhood pressure, reducing lift at high speed, decreasing the dense hot air pocket under the hood (cold air was drawn in front the front / under of the car, and then hot air was forced out the side vents, evacuating the underhood compartment). Engine power and performance was increased 'slightly' by lowering the engine bay temp to cooler levels. Some track times were reduced because the dense pocket of air under the hood was rapidly expelled, and it didn't build up under the front end, creating a naturally designed drag effect.

So, what's a cheap way to get more cold air into your engine bay and more hot air out? Simple. Go pop your hood. Look along the very back of the hood, see that rubber strip? Good, now that is GM's way of sealing off your engine compartment from the rear. A well known drag racing trick is to elevate the rear of the hood a few notches to let underhood air escape. But, you don't want to drive around with your hood's rear sticking up a half inch, now do you? Good. So, just carefully take that rubber strip, and remove the plastic tabs that hold it in. Don't worry, water isn't going to get into your engine bay, and if it does, it'll just run down the firewall. No problem. With the rubber strip removed, you should have a 1/4" to 1/2" gap at the back of your hood, with your hood sitting perfectly aligned with the rest of the car. Now, when you are driving, the ram air effect will bring cold air into your engine compartment and force hot air out at the back of your hood, near the base of your windshield. I would be careful when I removed these tabs, you may want to reuse them and the rubber seal later. Take your time, be a professional, remove it the same way it was installed, and then store it. If you don't need it in a few days, weeks, months, years, throw it away.

Sharp minded people here will realize that if we force hot air out at the base of the windshield, we start heating the cowl boundary layer of cool, dense air that our hood scoop draws its charge from. I don't think this is going to be a great big problem, I think we will be heating the aft edge of this cooling pocket, the scoop is situated far enough ahead of the thermal exhaust venting that you should still be able to get a good charge to your air cleaner assembly.

There are two ways to improve your stock TBI unit; rebuild it or scrap it and go with a pre-built better unit. I vote for the latter, since buying a larger TBI unit is cheaper than all the 'little' mods you can do to the stock unit, and comes out to be better in the end. You can truly 'nickel and dime yourself to death' with the stock unit and all the mods out there. If you want to keep your stock unit and mod the hell out of it, then Turbo City offers many modifications for your stock TBI unit.

A TBI spacer fits directly under the TBI unit, on the manifold itself, and raises the injector above the manifold, increasing air flow and velocity, thus increasing power. You might even be able to put two spacers under your TBI unit, depending on hood clearance problems. One should do you just fine. Another cheap modification ($20) is a TBI injector spacer. This 'other' spacer raises the actual injector housing within the TBI unit, creating air flow increases of as much as 7%! Again, you may be able to use a second injector spacer to make even more flow increases depending on hood clearance problems. It's your call based on what type of hood you use, stock or aftermarket.

Your next step is to move up to a high flow throttle body assembly. This modification is one of the most expensive of the TBI mods, but offers the highest individual performance gains. A larger throttlebody assembly can gain you up to 20% increase in air flow. The larger TB assembly offers much less restriction on the flow than the stock unit, increasing flow velocity and decreasing blockage to the flow. Once we have the larger throttle body assembly, we're going to want some larger injectors to use to squirt the good stuff into that larger throttlebody. TurboCity provides flow matched injectors for about $70 apiece (and you only need two! With TPI, you would need eight!). Flow matched injectors cut down on the individual variance in the duty cycle between the two stock injectors, as much as 15% or more! DIOADIR! Flow matched injectors result in a smoother running engine and a slight horsepower gain. You'll need the meter body gasket kit and the fuel nut gasket as well. Order a handful of each, just for spares! Flow matched injectors are a MUST if you are going to run the TBI unit on a four barrel single or dual plane manifold!

The next step on the TBI unit is a adjustable fuel pressure regulator. This unit allows you to fine tune your fuel pressure within the factory parameters of 9psi to 13psi. Upgrading to a better capacity Manifold Absolute Pressure (MAP) sensor is also required for our performance mods. To feed our new, thirstier and hungrier TBI unit, I would suggest a high pressure TBI fuel pump. TurboCity sells one which is capable of over 200% more pressure (25psi to 30psi compared to the stock pumps rating of 15psi max). It's a direct replacement for the stock (in-tank) pump and will allow you to run higher fuel line pressure (higher injector pressure) and gain even more horsepower.

Our total mods so far for the complete upgraded TBI unit should be less than the cost of a set of aftermarket intake runners and manifold for the TPI system!

Does all of that sound too complicated? Want a replacement TBI unit with 2" bores, direct bolt in capability, hooks up to the factory wiring harnesses, will talk to your ECM with no problems, and has a built in AFPR? Sound like a dream? Nope. Look at this:

OK, pop your eyeballs back in, roll your tongue back up, and wipe the slobber off of the screen. This unit is available from JEGs or Holley. You see the price is actually CHEAPER than what it would take to rebuild the stock TBI unit using the various Turbo City prices. This is the unit I plan to use on my L03 buildup for these very reasons, as stated by Holley:

Total flow now should be in excess of 670cfm, about the range of a good street Holley or Q-jet carb, more than enough to feed a healthy small block, even the awesome ZZ4 or ZZ430 engines! With some simple tricks (TBI spacer, extra gaskets, etc.) you can increase the flow to over 700cfm. The difference between a 670plusCFM TBI and a 670plusCFM carb is that the carb sucks. Literally. With the TBI, you are forcing the fuel into the intake, with the carb, you're just sucking it in. No control other than your right foot, some adjustment screws you fiddled with yesterday afternoon, and prayer. With the TBI system, once you mash your right foot down, the computer does all the dirty work for you. You might think about adding a higher capacity in-line fuel filtration system. Holley makes an excellent in-line filtration system, but the final call is ultimately yours to make. Your fuel system is another area where you need to DIOADIR. You don't want a little piece of trash to wipe out your new system. When you drop and drain your tank for the new fuel pump, clean your tank out thoroughly, and you might even think about coating it.

Our next step is the restricted intake manifold. Where the TPI system feeds through a (by factory standards) massive intake, the stock TBI is forced to inject fuel through two very tiny (1 11/16") openings. The TBI manifold further dispels the notion that it is a 'smart carb' by anyone who looks at the top of the intake manifold. Those two, tiny holes? That's where your TBI unit squirts the fuel. Yeah. Sad isn't it? So, even though you've increased the amount of air going into your engine, the L03 is still being choked to death by the factory intake manifold. That can't be 'smart'.

You can port the factory manifold, but I don't have the equipment to test flow consistencies, etc. so I let people who have this kind of money and equipment do it for me. Another excellent choice is the Edelbrock Performer TBI (pictured above) aluminum intake manifold. It's lighter than the stock unit (losing weight is always good) and offers Edelbrock's excellent experience with porting and flow matching. You'll get a noticeable increase in power across the RPM band. However, since the Edelbrock unit is built to reuse your stock TBI unit, the venturi intake ports are only 1 11/16th inch diameter. This makes it a bad design to use a larger TBI unit with.

If you are thinking of running the larger Holley ProJection 670cfm TBI unit with the factory harness and connectors, you will need to go to a manifold designed for the larger 2" intake ports. The Holley Pro-Jection intake manifold (pictured below) is one possible answer. Here is the Holley / Weiand Pro-Jection version of the Edelbrock Performer TBI manifold. The bore size is 2" for the larger Holley unit that we will be using. It bolts right up to the 305 or any Chevy small block. The part number for the unit is 300-66.

Holley makes an adaptor plate which allows you to use your TBI unit on any manifold that will accept a four barrel Holley carburetor, which is 99.9% of all aftermarket manifolds out there. This allows you to bypass the restrictive intake passages all together and go with a more conventional manifold design such as the Edelbrock Performer series or the Weiand 'Stealth' series of manifolds. I would recommend this route if you are planning on moving up to the larger TBI injectors and unit as it makes porting the manifold unnecessary. Here is a pic of the Holley unit, part number 17-45 and is available directly from Holley. Using the adaptor plate, you could use the 670cfm Holley TBI injector with one of Holley (or another company's) four barrel intake manifold.

For intake manifold choices, it is hard to beat the Edelbrock Performer series aluminum intake manifold. The Performer comes in three varieties; Performer EGR, Performer RPM (non-EGR), Performer Vortec (for use with GM's new Vortec series heads which we will address very soon). There is also a Edlebrock Performer TBI intake manifold, but other than light weight and a better design, it still is produced with the smaller (factory) diameter bores. You might can bore this manifold out, but there is just a better way to go if you use the 'four barrel' intake manifold and a TBI adaptor plate to install the TBI unit to the manifold. This offers the biggest intake area for the air / fuel mixture. Turbo City and Holley both make adaptor plates so that you can mount your factory TBI unit (or the 670cfm Holley unit) to any manifold which will accept a four barrel Holley carb.

While we are at it, lose the anemic stock heads. They are pitiful for performance use. The bore differences between the 305 and the 350 mean that you can't bolt 350 heads on a 305 without running into major valve to bore clearance problems. Heads for the little 305 are few and far between, but they are out there, if you know where to look. World Products makes an excellent series of heads for the 5.0 liter Chevy V8 with their Sportsman S/R Torquer heads. While somewhat pricey at upwards of $600 a pair (assembled), they are more expensive than the GM Vortec heads (which we will discuss next) but have their own advantages. With a intake bolt pattern which accepts either early or late model manifolds, the heads come with 58cc chambers. This means that they don't have to be milled to maintain a good compression ratio. Another advantage of the S/R Torquer heads for the 305 small block is that the valve angles are altered so that no valve to cylinder wall clearance problems will exist. The heads are assembled with 1.94 / 1.50-inch valves and valve springs and have screw in studs.

GM also offers a tremendous value for your buck in the Vortec series of heads. The L31 Vortec heads are available for about $400 per pair, assembled, from a variety of GM dealerships both in the real world and online. The Vortec heads feature the same 1.94 / 1.50 valve configuration as the S/R Torquer heads do, but with a more traditional valve angle. Even with these 'smaller' valves (the stock 305 valves are 1.84 / 1.50 size) as compared to the more traditional 'double hump' or 2.02 / 1.60 valves as found in the Bow Tie cast-iron heads and in the upper price aluminum GM Vette heads, the Vortec heads still outflow the larger valve units. However, the Vortec heads have a price to pay in that they require careful installation. An article in the March 1999 Car Craft detailed the installation of the Vortec heads on a 305 small block. In the article, it was stated that the Vortec heads have a unique intake manifold bolt pattern requiring a special and costly GM or aftermarket intake. Indeed, the Edelbrock Performer Vortec aluminum manifold is almost 40% more expensive than the regular Performer manifold! The valve cover bolt holes are the centerbolt design, meaning that early blocks and installations will have to switch over to the post-'87 center bolt valve cover design and late-model guided rocker arms. The heads have a volume of 64cc which will require milling in order to avoid compression loss on a 305, and the larger-diameter chamber outline requires that you use 350 head gaskets, a solution which could also cause a loss of compression. Car Craft milled the heads 0.045 inches and used a thin 0.015 inch head gasket to bypass these possible problems. With this work done, CC managed to maintain a CR of 10.0:1 on the small block with no detonation problems, even using 89 octane gas, once the L31 Vortec heads were installed.

For my money, the World Products heads are the better choice. Less hassle and direct bolt on with no special manifolds required.

Your motor should be set up already for roller lifters, so why not go back with some good quality replacements. The roller tips on the lifters reduce parasitic power loss due to friction (and reduce heat), resulting in more power (every little bit helps) and longer life of internal components.

Camshaft Choice	Stock L03	Edelbrock Performer Plus TBI	Edelbrock Performer	GM LT4 "HOT"
Lift: intake	.351	.265	.280	.476
exhaust	.386	.294	.295	.480
Duration: intake	180	244	278	203
(crank) exhaust	196	264	288	210

You can see by this chart the various cam specs. The sticks from Edelbrock appear to be pretty tame in comparison... Here's how they stack up against the other so called hot cams of the F-bodies, just for some kicks and reference.

Engine	LB9 5.0 TPI (good cam)	LB9 5.0 TPI (peanut cam)	L69 High Output 4V carb (Corvette cam)
Lift: intake	.404	.350	.410
exhaust	.415	.385	.423
Duration: intake	320	307	320
(crank) exhaust	320	311	320

When installing a cam, always install a cam button behind the timing cover. It's basically a plug that keeps the cam from walking forward (as roller cams are sometimes prone to do), and it's cheap insurance even on non-roller cams. Many motor builders install cam buttons in their buildups. Get a nylon one for best results.

I'm still doing research on what type of camshaft to use, but I'm wanting to stick with a full roller, roller lifters, with a set of 1.6 roller rockers to top it off. When I finish my camshaft selection, I'll let you know. Stay tuned. Those of you with any good references to camshaft selection on the 305 for EFI, let me know. I'll give you credit here. I see a lot of opportunity for power, but most of the reviews that I read give very impressive power gains (like 40hp!) just with a cam change but then say stuff like "We went with the relatively mild camshaft choice...". I'm looking for something with a good rump to it, that will be good all around for daily driving, acceleration, and performance.

When redoing the valve train, you will also want to switch to a better timing chain. A double roller like Edelbrock's true roller double roller timing chain is a good choice, but many companies produce similar units. Also, a double idler timing gear set will free up even more parasitic horsepower loss because all timing chains eventually 'stretch' and loose some of their ability through simple mechanical and physical 'slack'. They 'walk' and when they stretch, the extra lash in the chain leads to timing inaccuracies across the power band. The timing gear is a rigid set of gears, and as such, does not 'stretch' or 'walk' with age. It keeps your timing constant, at all levels of the power band, as long as it's installed. You cannot use a 'noisy' gear drive with a motor that uses electronic engine management as the 'noisy' gear drive may fool the knock sensor into thinking the noise generated by the gears is detonation. This will result in the computer retarding your spark and timing for a loss in performance.

Parasitic power loss is a big problem on the 5.0 liter engines, carb, TBI or TPI. This is the 'extra' horsepower that it takes to drive your accessories; power steering, water pump, etc. Using a set of March underdrive pulleys, you can slow down these accessories, allowing them to spin slower, using less horsepower, delivering the same performance, and lengthening the service life of your accessories. Once you free up this 'parasitic' power loss, it means that you get more of your hard earned horsepower (and torque) to the rear wheels, instead of wasting it on running your accessories at speeds that they don't really need to be run at in the first place. This is one of the most cost effective mods you can make to your 5.0 liter base motor but it also works VERY well when used in conjunction with all of the other modifications. Your only real choice here is steel (painted black, which I prefer) or shiny aluminum (which adds to the price!).

Your ignition also needs to be addressed, as the factory ignition is somewhat limited for what we are building up. All the increased, richer intake charge isn't going to do you any good if you don't have the spark to burn it with. I would go with a good MSD or Accel unit, the two names that I trust from experience, and pony up the extra cash and get one with an adjustable rev limiter. Better safe than sorry.

A good setup is the MSD 6AL(X) series control box with a MSD Blaster Coil providing the firepower. A high performance distributor (MSD small top or other) is also a good idea. Accel makes an excellent ignition system in the 300+ system, which, if you have the money, is the better choice, IMHO. The 300+ system is a complete digital system, with adjustable rev limit control and plugs into your factory HEI system easily.

For plug wires, I would go with some MSD 8.5mm SuperConductors. Lowest resistance per foot, spiral wound and highly heat resistant. Accel makes some excellent wires as well. Get a wire loom set, and make sure that the wires don't come into contact with your headers, even if you have wrapped your headers / exhaust system with thermal wrap. That and a nicely organized engine bay wins points with the people in the know, as well as at car shows, and the local car hop / garage.

For spark plugs, forget Split Fires. They are a joke and a waste of money. A good AC Delco spark plug, properly heat range mated, will work wonders. Bosche makes a great platinum plug, and I've heard that the new Bosche Platinum +4 plugs were good for 14 horses on one engine. I'll believe it when I see it. It is hard to beat a AC Delco spark plug, get the right heat range!

While you are at it, make sure that your alternator is putting out the proper power. On EFI based motors, the computer handles all of the work load during performance operations, so having a computer with power shortages is not a good idea. Make sure you have a powerful enough alternator and battery to handle all the electrical load of your high-tech power plant.

Now we're getting somewhere! We've removed the restricted air intake system, cooled down the incoming air and lost the underhood high temp. We've modified the factory TBI unit to flow equal to or better than a high performance 4 barrel carb, and it's certainly going to be smarter at doing the job thanks to the computer and the aftermarket programmed performance chip. The engine has lost some much needed weight and gained some serious power by replacing the stock cast iron intake manifold, cylinder heads, and exhaust system with lighter weight aluminum models, higher flow models, and a complete high flow tubular exhaust system.

We've addressed heating and cooling problems, intake and exhaust, internal efficiency, fuel delivery, and parasitic power loss attributes. Now we have a solid performer engine, built for less than a TPI buildup. We now have a L03 engine that is making the same or even more horsepower than a stock 5.7 liter TPI engine! Easily! Our L03 will now run circles around a stock TPI engine of either displacement, and will embarrass even some built up TPI engines and certainly anything that a Mustang can throw at you.

Now you have a monster of a 5.0 liter L03, powered by the 'wimpy' TBI system. That's what you want others to think. If you've done your engine right, the details will be hard to spot, and blind to most. Wax a few TPI cars, and smile when you show them what appears to be a stock L03 TBI setup. They might notice the cowl scoop, or your fresh air intakes, but if you've painted the new manifold, water pump, and heads the same drab old black, then spotting this is going to be hard under all that emissions junk.

Can you say "Sleeper"? I thought that you could. Still not happy with the L03?

If you've got it, stroke it! Your final step is to stroke your 5.0 liter. That's right! Drop a 400 small block Chevy crank into your 305 and you get 335cid! This one modification alone, as done by Super Chevy magazine, with a plain old factory Q-jet carb installed on a Edelbrock Performer manifold, a set of headers, and a mild, mild cam, running 5.0 H.O. heads and a mild stock compression ratio, made for almost 100 horses over stock!

Now, let's assume 100 horses over stock, which would yield a 270 horse monster out of a stock 305 cid using a Q-jet. 270 horses and almost 320 ft/lbs of torque! See how much your engine is getting stronger? OK, let's add in all that we've done above, put on the excellent TBI system that we have built up and see if Tokyo can stand up to our small block L03 version of Godzilla. With a hotter cam, I've seen a 305 stroker see 300 horses, that's almost 1 hp per cubic inch, and far more potent than even the 5.7 L98 TPI ever was, stock. Imagine a Formula 350 being waxed by a Formula TBI. We're talking LT-1 territory here, folks, from a lowly, unloved L03 TBI engine!

Anyone who recommends that you take your TBI, yank it off, and throw it as far as you can is a low tech hill scoggin.

The company you are looking for to purchase the stroker kit from is called "Powerhouse Power plant". they just came out with a new kit called the "305 stroker 335 kit". it includes a stroker crank, 10:1 pistons, new ring set, CR1 5.7" rods, rod/main bearings all for just $599.00. you can add a new balancer or flex plate for an extra $75 and the whole assembly is balanced from these good people for just $90 or so more.

Info line: 661-861-0167
M-F 7:30-5:30 P.S.T
Sat 8:00 - 2:00 P.S.T.
Orders only: 800-200-7693
web page: http://www.enginekits.com
e-mail: powerplant@lightspeed.net

The Fluidamper Streetdamper (same thing as the regular Fluidamper, but cheaper, and not SSI legal for racing, so save a few bucks if you don't plan on doing any SSI legal racing) is a good choice for this motor as well as a lightweight aluminum flywheel, and be sure to have your entire rotating assembly balanced. Choose only the best component parts, don't go cheap on things for the inside of your engine, it's got to last! Remember, DIOADIR! With lighter rotating mass and reciprocating mass, and a stroker crank, your 305 will scream like a whipped banshee. The old adage is true, there is no substitute for cubic inches, and with the help of the larger crank, your boat anchor 305 will terrorize larger engines. Super Chevy said that they were VERY impressed with the 305 stroker.

So, you still think you should chuck your TBI and 5.0 liter L03? Think again! Contrary to popular belief, the L0 in L03 does *not* stand for "Low Output". It stands for "Lots of Opportunities", but only if you are smart enough to recognize the L03 for what it is; a diamond in the rough, a hot rodder's best friend.

The 305 has been shown time and again to live up to Lingenfelter's golden rule of 1.1 horsepower per cube. On a stock 305, this equals 335.5 horsepower. Amazing, since that is the amount of cubes you get if you drop the 400 crank into the 305! Odd! Imagine what a 335 could make with the 1.1 Golden Rule? 368 horses? That's more powerful than a stock ZZ4 engine!

Here are a few more links to building up your 305 into a pavement ripping torque monster!

Just a few more links to articles that only go to prove that the 305 is a more than capable very high performance engine. So exactly how much power do you want out of your 305? 200 horsepower? 300 horsepower? 400 horsepower?! All naturally aspirated with no power adders?! Read on!

Still think you need a 350 with TPI to get the job done? Think again ... Use what you have.

Don't go low-tech, keep your L03 and mod it! You'll be both surprised and quite pleased with your results.

"Because, everything in life just looks better in the rear view mirror."
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