a little help please

[TorqueAddict]

whats up guys im in the process of building a car for my cousin while he is on tour in iraq. the car is his 90 camaro rs with a 305 and t5 trans. his budget is about 3500 dollars to build it. mind you the factory t5 is going to need to be rebuilt and the car has blown head gaskets. i was thinking about a set of vortec heads and a cam would be pretty good, but i dont know much about 3rd gens so any help is appreciated. thanks.

[five7kid]

The weaknesses of the LO3 TBI engines RS's include flow-limited heads, tiny exhaust, a small cam, and the need to retune the computer when you make most any change. Add to that the near total lack of aftermarket support for the TBI system itself, and you're pretty limited.

You can do Vortec heads, but they had 64cc chambers (at least the "good" 350 Vortec heads are 64cc - the no-real-gain 305 Vortec heads have 58cc chambers). So, either lose compression, or have the heads shaved down to 58cc's to maintain compression. There is a TBI intake manifold available for Vortec heads, but it isn't much of an improvement. People typically get a carburetor intake manifold and carb-to-TBI adapter.

You need to keep the cam computer-compatible. The heads can only handle ~.480" lift (need to verify that for each valve when you have the heads) without modification to the top of the valve guide (which is a good idea, anyway, to get a better type stem seal installed).

The biggie is the exhaust - don't get ANYTHING for the TBI application! Start with Hooker 2055HKR headers (called out as the '86-'90 TPI single cat application), then add a direct-fit '86-'90 TPI single cat converter, and a cat-back for the same application of your choice. Unless you do the exhaust (and plan on budgetting at least $1000 for self-installed exhaust alone), nothing else you do will make much difference.

The factory single snorkel air cleaner falls in the same catagory as the factory exhaust.

[TorqueAddict]

thanks man im tryin to get this car done for him before he returns in october

[cocobolo95]

Instead of wasting time on the 305 why don't you find a good 350 tpi setup complete with wiring & computer. Craigslist usually has them or your local salvage yard. You will start with about 240 hp then you can do cam, exhaust, ecm chip tune.

[cocobolo95]

Or if your feeling real froggy try a 94 or newer lt1 for the car. From what I've seen they fit real nice in the 3rd gen engine bay. Just get computer and wiring again. I said 94 or newer because you can reflash the computer unlike the 93 or 92 where you have to burn a new chip.