I have a 91 rs camaro that I am putting a new motor in and am kinda having trouble figuring out what to do about the throttle body and all. Here are my motor specs,

350 roller bored .040 over,
stock roller lifters,
lo3 heads (for right now, soon to be vortecs)
new dish pistons ( about 9.5:1 with lo3 58cc chambers)
Performer tbi intake,
having a custom chip burned,
Lt1 cam.

I want to throw on a bigger throttle body like the 454 one with 2" venturies but dont know exactly what all is needed in installing it and what kind of computer stuff is needed. If you can help I would apreciate it.
Hip Hop

 

The custom tune will take car of any TBI unit that you run. You will deffinately need a 2" bore TBI unit. Either the Holley 670 or the 454. Both will need to be wired to your current harness. Whoever does your custom rpom will most likely ask you what TBI unit you are using. You really need to data log the car yourself and tune it accordingly based on your set-up, wahtever TBI unit is used.

 

1)Do not waste your money on the GMPP Vortec TBI manifold. It sucks, has 1 11/16 bores. Buy an Edelbrock performer Air gap vortec and buy a TBI adapter plate and just bore that out to handle 2" bores.

2)Go with the holley 670cfm TBI. Its closer to stock than the 454 TBI. If you go 454, you'll have to change IAC's, which I'm having trouble with the wiring, nothing seems to work. You'll have to switch the throttle linkages and if you have the GMPP vortec manifold, it hangs over the TBI plate on the manifold! Talk about a bitch!

If you go holley, you'll be able to keep the same IAC, but just convert over to the flat TPS, MUCH easier than converting to the 454 newer- flat IAC hookup.

Good luck.