I recently purchased a 1989 Trans Am with a TBI 305. I also have a 1984 Camaro with a 350 crate engine (pre 1987 cylinder heads). I want to install the 350 into the Trans Am and keep the TBI setup. I know that the cylinder heads on the 305 are a newer design than whats on the 350, so the TBI manifold will not bolt up. Can I simply take the heads off the 305 and put it on the 350 and bolt on the TBI manifold?
I also have a performer plus camshaft in the 350 that don't us roller lifters. Will this work with the 305 heads? If the 305 heads bolt on, what will this do to the compression ratio of the once 8.5:1 350?

 

you will bump the comp up a bit... usually the 305 had smaller CC heads to bump up the compression and make up the power loss of the 305... but the problem is will it breath enough to run the 350? specailly with a cam in it... a stock 350 will work with the 305 setup on top still not to full potential.. but work... you can do it it will all plug up and probably run fine depending how crazy the cam is... but your not going to see the full power of the 350 with that on top... still more than you have now thats for sure... would be an easy way to get you started then slowly upgrade it get a larger TBI and then maybe some better post 87 heads to go with it...

 

get injectors for larger engine,

 

Does the 305 have roller lifters? If so, will the non-roller lifters from the 350 work? Id like to keep the cam. Its a mild cam for low end torque. Also, does the knock sensor bolt into the cylender head or the block?

 

you could convert it over to flat tappet but thats kinda going backwards... you can pick up a performance roller cam for not to much just look on ebay even... as for the heads and everything they will bolt right up no problem.. and at most you might want to find the larger injectors like he said or just search the junkyard for a 350TBI they are all over the place in trucks and vans and you should be able to pick one up pretty cheep... TBI really isnt a power maker just a lap between carb and full out fuel injection... but holley and a few others do make some nice performance TBI stuff...

 

TBI is whatever you tune it to be. Set up properly it has enough capacity to feed almost any street driven 350. Given the many choices of intake manifolds, I'd much prefer to build horsepower with TBI than TPI.

Mr. Trans Am, what's the specs on the performer plus camshaft that you have?

 

I just re-cammed my 350 crate engine for fuel mileage and torque. It had a decent cam in it and I pulled it to put a peanut 305 roller cam in it. The heads have been lightly cleaned up and I have headers, full exhaust, edelbrock intake, ultimate TBI mods, and tuning with the EBL.

It is in a 5,500 lbs tank. Here are the results

YouTube - Chevy Van 350 1

YouTube - Chevy Van 350 2

I could only imagine what it would do with 2,500 less lbs!

 

[QUOTE=Fast355]I just re-cammed my 350 crate engine for fuel mileage and torque. It had a decent cam in it and I pulled it to put a peanut 305 roller cam in it.

IQUOTE]
That is totaly insane!
The only place that cam should go is in the trash!

 

true but the stock chevy TBI is still limited by the size... its not a 4 bbl holley TBI or anything...

 

Now I see what you meant. The stock Rochester 220 flows about 490 cfm ...not enough for a healthy dual-plane 350. I'd estimate that the Ultimate TBI mods can get it up to the mid-500 cfm range. Turbo City's modded 220 comes in at 590 cfm ...up to 620 cfm with an injector spacer and some light grinding and smoothing. I think 620 cfm is plenty on most healthy 350s (especially with a single plane manifold, or open plenum/spacer) ...but, like you point out, that's a heavily modded unit - not the plane stocker. I thought you were just saying the old "TBI can't make power" line ...my mistake.

 

oh no i know what TBI can do and how easy it is to tune and perform... im looking into the holley 900cfm setup for my 383 right now its probably the easiest way to go fuel injected on a pre 87 block still keep the WOT power of a carb and get the better fuel millage and trottle response of a FI engine... but based on the fact he had a stock 305 TBI i was guessing he didnt plan on doing all that... i heard the 454 TBI swap to a mild 350 is a good choice too... east to find in any larger truck or a chevy SS truck and still using the same wiring...should be able to support a 350hp motor with not to many mods to it...

 

The camshaft I have in my 350 is the Edelbrock Performer Plus. It is a mild cam for low end torque. At 0.050, the intake is 204 and the exhaust is 214. It should be great in my Trans Am because of the stock gearing.

 

[QUOTE=Dyno Don]That maybe true for a lighter car application, but alot of us are truck TBI guys here. The cam is small, but you can't beat it for low-end torque and fuel mileage. I can be doing 70 mph @ 2,000 rpm, uphill, give it 10% more throttle and accelerate to 90+ without difficulty while still in OD. Low-end torque is an understatement.