saw this in summit racing and was thinking of buying it. has anyone else bought this kit? did you get 425 horsies? does anyone have a cheaper way to get 425 horses with similiar parts? if i take my lt1 from my camaro and send it to the engine shop tell them that it use to be a lt4, will the use these parts on my engine? also with if i use this package and make the bottom end a stroker? whats a good 396 set-up that has serious horsepower and will be able to take a supercharger later on without going to pieces? if the engine is built solid enough, can you supercharger past 9 psi without using race fuel and not have to worry about detenation? maybe in the 15 psi range would be nice.

NAL-GMP3287-1
Turn your LT1 into the engine it wants to be.
Have an LT1, but want an LT4? GM Performance Parts has what you need. These LT1-to-LT4 conversion kits bring the most out of your factory LT1 engine. The kits include LT4 cylinder heads with valves and springs, a red aluminum LT4 intake manifold, GM Performance Parts' hot cam with 1.6:1 ratio Bow Tie roller rockers, and all necessary gaskets. The result of all of these mods is 425+ proven horsepower!

 

Okay...the LT4 is about as useless as a one legged man in an *** kicking contest. You might see 330-340rwhp out of it depending on tune. It's really not worth it unless you need to buy heads because you don't have any. Then it still needs port work and a more aggressive cam to wake it up. Anyways....for this 396 you are thinking of building.....
-Rethink the blower. While it is true you can make awesome power with the superchargers, turbo LT1's are sick and have some crazy good track times to prove it. No offense to any supercharged lt1 guys out there.
-You can run as much boost as you want with the right tune, compression etc. Most guys run the race gas so they can have more timing in the motor with more boost. A 9:1 fully forged motor could probably live at 15+psi (w/ intercooler) on 93 octane. Possibly more depending on other variables.
-Headwise is up to you. You have several options. AFR 215 raised runner heads would work extremely well on forced induction...i.e. they flow a lot. Ported stockers would definitely run out of breath on a 396 alone, not to mention a supercharged beast. Which leads me to potentially your best, albeit most expensive, option.....gm615 heads. These are canted valve (15*) heads and are used in many race applications. Look a N20DAVE's motor on here, same style heads, different brand....makes SICK HP N/A. With these heads you would need all new valvetrain, custom pistons (you're getting those anyways with your low compression 396), and a different intake setup. If you did everything right your HP level could be 800+, or with stock ported heads done by a local porter, you may see only 470-500rwhp. It depends.....how much $$$$ you got?

 

ok to go from 350 to 383 you need to either bore the heads and get bigger pistons or get a bigger crank to help produce the extra space, (this is what i think i understand but am not to certain about) so to produce a 396 i would have to do both???? and what kind of internal parts do i need? after it gets bored out, what size do the piston heads have to be? and dont they have to be liquid nitrious super forged titantium piston heads and connecting rods. ok maybe besides not being too sharp on blocks, im not on the top of my game on materials either. but i do know forged is better that cast, or that only when talking about cranks? and i'd like to get the most bang for my buck, im not exactly bill gates when it comes to money, i would think im closer to mike tyson (im kinda sas he lost his last fight, matter of fact its kinda pathetic what happened to him, i remember lookingup to him as a child and playing mike tyson punch out, now i guess its mike tyson getting punched out) ok back on track, id like a good bottom end to start off with. then i wanna get the nice heads and cam to compliment it, AFR 215 raised runner heads sounds good. im not trying to get too carried away. this will be my daily driver. and turbos actually make more horsies than superchargers? i was thinking twin screw (i wanna kenne bell but they dont make them for lt1s) but dont turbos have a lag time?

 

To make a 383 you have to increase the length of the stroke ( different crank ) You would pretty much be a fool the rebuild an engine without reboring the cylinders. Reboring them will make then engine seem like it is brand new. Perfect cylinders etc. You will have to do the exact same thing on a 396. There are also alot of variables out there that are going to determine your power. Biggest factor i can think of is how thick your wallet is

If your looking into forced induction, i would check out the FI section of this board, head over to camaroz28.com and check out their site ( more lt1 based ) You will realise there is alot that you still need to learn. And i cannot stress enough that if you do your research and know your goals, you will come out with a better, cheaper product in the end.

And to answer your question about the lt4 kit. It is essentially a waste of money. If your wanting just a heads cam setup, and want to be close to 375+rwhp then i would look at one of the head porters on the net. Lloyd Elliot is the first person to come to mind. You can get a very very nice setup off him for about $1600 + the cost of shipping ( you have to send him your cylinder heads, or purchase a used set of stock heads ( prolly about $250 )) This includes cam, porting of heads, valves, springs etc. But like i said, do your research.