Swampboy wondering what to do with this new toy. Stock 1995 Lt1 auto.
Would like to increase power and torque at wheels to about 400 hp. I would like the mods to be described brands and specs for each item for a true build, heads and all their parts, etc. Then the cam to move it all finally the intake system to feed it. We can talk transmission and rear gears also if someone has all this down. I WILL SPEND THE MONEY. I am going to drive it on the street. Not my daily driver but when the weathers right and I just itching to go race it at our nearby track quarter mile and circuit track.

I've been watching and reading the forum and there is a lot to grasp. Don't what a pure drag car. So suspension mods are probably necessary. Running Michelin Pilot Sport A/S basic stock suspension. Have the Dewitt aluminium rad. never messed with OBD. I'm guessing that will be necessary too. A lot to ask but i have read some very impressive comments. I know the right guy is out there just ready to break my corvette savings. Thanks in advance.

 

Start with a CC306 cam and a set of headers. That should wake it up a little!

 

That sounds easy enough. Any particular header and exhaust system. thanks man

 

Not really sure, for headers, just get whatever the cheapest long tubes are. They all do the same essentially. Exhaust design is a little different. The stock exhaust should be pretty decent.

 

I stuck my head under the car briefly and noticed the exhaust pipes seemed pretty large like maybe three inches in diameter. I need to completely investigate the car. It has a really cool tone and its pretty quick. Clean clean clean engine bay. So keep the stock heads, intake manifold and fuel rails. do i need to re-tune the OBD after the additions you mentioned. I sound green but have experience with engines. thanks again. 90,000 miles.

 

Yes it's going to need a tune. The LT1 is a good foundation for bolt on and mild modifications. Heads are decent, intake is decent, exhaust is decent. You can also go with like 3.73s or something if you like. I know in the 6 speed cars, going to 3.73s didn't really affect your top speed because the stock engine couldn't pull it up all the way in 6th gear.

 

I haven't installed my Lunati 60120 cam in my L98 yet, so can't comment on it. But while I was shopping around, I read a lot of people were happy with this kit.

http://www.jegs.com/i/GM+Performance...FStnOgodgjYAOA

 

I had a good feeling i would receive logical mods just to give the car a little more power than how the General built it. Now that i have a vette i can't seem to stop wanting another one like 1995 ZR1, 2009 ZR1 maybe an 2014 ZO6. Went to the Auto Show in Detroit all the way from New Mexico just to see all the fast cars. I am hooked. My wife is supportive. i just need to finish the engine rebuild on her original 1949 MG TC RH drive packing a whopping 85 hp but it is beautiful. Just about got the two SU H type carbs rebuilt and its done. We also own a 1955 Buick Century completely restored 322 nail-head pushing about 230 hp. Came across this 1995 vette and the fever has returned from my teenage days owning a 1970 GTO. Fast but better stay straight. I have been fortunate and try to stay humble.

 

I don't post much in CF tech any more but this thread has so much FAIL in it that I am going to drop in my nickels worth.
CC306 with stock heads shortblock are not going to give you anywhere near 400 RWHP .

If you have the stock 2.59 rear end gearing your CC306 will have ****** drivability.(306 is a big lumpy cam , with stock heads converter and gears you will probably have CAM SURGE )

In order to meet your 400 RWHP goal you need to look at your car holistically.

You should match components that complement each other. CAM matched to the cars weight, " engine", converter and gearing.
IMO you can't go wrong with a GOOD HEAD CAM combination, and the proper stall converter with a stock D44 out of a m6 .

Save yourself money and a headache don't go for cheap headers they will rust and leak. Search forum you will see how all of this used to be discussed daily.

Mike

 

Didn't Realize He Said RWHP.

 

Someone else here will be able to help you more in depth but I am also in the middle of piecing together a heads/cam swap like you are describing. So I will share what I have learned so far myself through research.

First you said you are looking for 400hp/400lbft at the wheels. You will not be able to achieve both of these numbers with a stock bottom end. You will need to stroke to a 383 in order to get that torque and hp. 400rwhp can be done on the stock bottom end and is done all the time in F-bodies however you will only be looking at about 360ish lbft of torque. This is what I am shooting for 400rwhp/360lbft.

Intake: just have yours port matched to a bigger throttle body (52mm or 58mm) as well has having the runners ported to match up with the heads you choose to go with.

Heads: There are several choices when it comes to heads. I personally bought a set of lloyd elliot stage 2 heads which flow great and are not that expensive. Other popular choices are Advanced induction (stock ported heads like lloyd elliot) and AFR (These are by far the best but you will pay for it)

Cam: This should be done to match your heads and everything else with your build. The best way to choose what to do with your cam is to talk to however you end up having do your heads. Tell them what you are looking for and they will tell you what will work best for you to achieve your goals. To get 400rwhp you will need a big cam. This will not be an emissions friendly cam, you will lose drivability and you will have a choppy idle.

Valvetrain: You are going to need some much stiffer springs and you will want roller rockers. Talk to whoever is recommending your cam about what ratio to get the rockers. Also you will most likely need bigger valves for the ported heads. (Talk to who is supplying the heads.)

Headers: There are not many options for true longtubes in a LT1 C4 and they are all expensive with the exception of OBX but they require modification to fit. American Racing, Stainless Works, Melrose, and Exotic Muscle are all options. Do some research about them from existing threads and choose which is best for you.

Drivetrain: You will need a higher stall for the required cam to reach your hp goals. You will also need some steeper rear gears. You also may want to look into replacing you D36 with a D44 from a manual C4 depending on how hard you are going to bang on it at the strip.

Other good accessories: Electric water pump will free up about 8 to 10hp, Underdrive pulley will free up a little more as well. In order to reach your goal all the little things will add up to make a difference.

In the end 400rwhp is attainable in a stock bottom end LT1 you just really have to work for it and you cant cut corners. There are a few cars on this forum doing this but don't limit your research to just this forum. There are a lot of F-bodies on a popular F-body forum making over 400rwhp and a lot of information about it on that forum. From my experience I have found that LT1 F-body owners are more aggressive in their builds than LT1 Vette guys are on average. However F-bodys do also seem to dyno about 10-20hp higher than Vettes.

Good luck with your build.

 

Dude- it's a one-stop shopping experience for your horsepower goals, you choose which one you're more comfortable with;

Elliot Port works;

http://elliottsportworks.com/

Advanced Induction (my choice);

http://advancedinduction.com/

both vendors offer a full valve-train, intake, and head's package. The key here is that they will use your existing castings (stock heads and intake) and port them to achieve the power you're after. The coolest part is that it will look totally stock!

Next, I would step to a 3,000 stall, with 3.73 gears (even 4.10's if you're cool with it, the trans will still have a happy highway cruising engine speed), MT ET-II tires, and QA1 single adjust or dual adjust shocks (retaining the stock transverse leaf).

The issue will be keeping the transmission and differential together, but this package will EASILY yield 400rwhp and mid-11 second quarter mile times!

 

Many thanks to all who have posted. If i don't bore the block can the mods be made with removing all front end components (shroud Rad, opti, water pump, etc.) and of course the complete top end (intake, heads, etc.) including replacing the cam. Or do i need to yank the engine. How will the 3.73 gears effect top in speed.

 

Top speed is done in 5th
You can get 400 to the ground but it will be a bit rowdy. Youll need a stellar cyl head and some aggressive cam timing and have to wind/gear it to the moon;If you have ported factory heads even worse manners to get there
Do you mind setting lash 1-2x a yr?

Easier and more tractable to stroke it to at least 383 a good 210 comp port head and HR cam 236-242@050 intake (lots of choices out there) with the intake ported headers etc etc. Usually a larger arm in the motor gets us that feeling we are looking for from the cam/heads on 350s.

 

Bingo! We have a winner. Get a package from one of these two lt1 experts. Get it professionally tuned. 400 whp is achievable. Need converter, 3000 is good for street car. But 400 whp heads cam combo will need 4000-4500 to move best for drag. Stock cube lt1's dont make alot of torque below 4000. Same as any short runner intake motor

Car will move fine on 2.59 gears. Fbodys move fine on 2.73's with higher stall converters. Gears help optimize but not needed just yet.

 

Buying the cheapest headers is really not good advice..They will rust out quickly. Cam choice will depend on many things..Not just buy this cam ...

 

I own older solid lifter cars which require adjusting regularly. I have never adjusted hydraulic lifters before i have set preload requirements. So lash will occur with this type of aggressive set up?

 

With a good head port, theres no reason you cant have 400 whp by 6400-6500 rpm. Thats as high as you want to go on stock bottom. A real good port intake and cam could make that power by 6200 but you need a hell of a system from intake to header collector

 

If you have $6,000-$10,000 sitting around for just a motor, than this is an option....

If you want to be budget minded and have even more pleasure running 11's and making 400rwhp with the minimal parts and cost, stick with the stock castings. You won't need a solid roller cam, a good cam profile on a hyd. roller cam will work fine.

"gears" will make up for the lack of low-end torque, and it's advised when you step up to a performance cam. It just "wakes up" the car.

It is critical to make sure your stock bottom-end is healthy. So you need run a leak down, and other evaluations prior to asking more of the combination. Some items should be replaced as a safety measure (water pump, possibly the oil pump, possibly look into ARP fasteners if you have the pan off, timing chain, lifters, etc.).

Full package from AI for 400-430rwhp is about $3,000. The external bolt-ons (like headers, and stall converter) will add up as well. I'd say $5,000-6,000 would be a reasonable budget for a true, well rounded package.

 

I visited the two recommended LT1 head modifier/port sites and each one re works the heads, recommends camshaft sizes and valve train systems for my goals, plus rework the intake manifold. I assume fuel delivery system will need upgrading also. Plus good headers and a street legal cats and exhaust pipes/mufflers. Then a OBD tune to match the mods. What do you recommend as HELL of an intake system and headers?