Hey guys I have a '92 Camaro with the 305TPI/700R4. It has 92,xxx miles on it and I am looking at crate engines.

Most of the ones I see are carb'd so could I just put my TPI system on it and call it a day? If that is possible, is it easy? (Something a kid could do?) Without having to machine anything?

So if I manage to make it TPI, would I just need a '92 350 prom and that's it? Seeing how the harness is the same.

Correct me if I'm wrong, but if I drop in a 350hp 350, I'm gonna have to tune my prom right? How hard is that?

-Peace

 

Most crate engines are '86-earlier intake mount bolt style - not a huge deal, but a detail that you will have to manage.

Many more crate engines these days are using Vortec-style heads. Not a bad move, but you'll need to get a Vortec-specific base for that (add $400 to your budget).

A 350 horse carb'd crate engine most likely wouldn't play well with your typical TPI set-up. The TPI hardware is pretty restrictive from a flow standpoint, and the "tuned" aspect limits effective RPMs to about 4800. Shorter, fatter runners are the first step to "cure" that. Plenum porting is the typical next step, that's covered thoroughly on the TPI forum. The base is also either ported or replaced with aftermarket. As you might gather, by now you've plunked down a pretty good chunk of change, and you haven't even gotten to the PROM tuning thing yet. It makes more sense to me to just get a Holley/Weiand Steath Ram intake set-up and go from there (requires a 58mm TB). You'll be starting with a better performance system, but you will give up the TPI "look".

Before I forget it, you'll need bigger injectors. For 350 HP, 24 lb would do. 19 lb is stock 305, and 22 lb is stock 350.

Now, PROM. The 1990-92 TPI systems are speed density (aka, "MAP"), which is very sensitive to hardware changes such as displacement, cam profile, exhaust efficiency, etc. So, figure on needing to tune it. You can go to the TPI and DIY PROM tuning forums to bone up on that. You don't need a 350 PROM, you can reflash the one you have. I'm already over my head, so just check out those forums.

 

Ok well converting carb to TPI is just to much work for me. The only help I'm getting is pulling the engine out.

Maybe I'm better off pulling a 350TPI/PROM out of a thirdgen and call it a day?

Maybe an LT1 would be easier?

 

LT1 could be considered fairly easy if you don't keep AC (have to notch the crossmember to clear the compressor, or fabricate a mount for the compressor somewhere else).

Pulling a '90-'92 350 TPI would certainly be the easiest.

Which exhaust do you have, dual or single cat? Or, already replaced with aftermarket?

 

I have a single cat but it's a 3inch flowmaster system. (Came on the car when bought)

I don't use my AC at all, windows down all the time so LT1 would be easy? What about prom?

 

The single cat system '91 & '92 was the small 2-1/4" cat. Pretty restrictive, needs to go if you are considering a bigger engine (too small for a 305, for that matter).

If you do LT1, the best bet is to get a complete f-body take-out engine/trans/harness/PCM (PCM replaces the 3rd gen ECM). The B-bodies also work, but be careful you aren't getting the smaller 4.3l engine. I'm not clear on the details, but I believe you can remove the AC compressor from the engine, then re-route or get an AC-delete pulley for the belt.

It will be more work than a 350 TPI take-out, but the results are pretty rewarding.

 

I don't need the AC, mine doesn't work anyways.

Is the harness and PCM just a simple swap or am I gonna have to custom my harness? Something I don't know how to do.

 

See the LT1 swap sticky above, or search the LSx/LTx subforum.

Basically you splice the LT1 harness, which has the PCM in it, into the car harness.