What all is needed to do this swap??

Also to complicate the matter we're thinking about using an older 2 pcs. rear main 355 with trickflow heads and a healthy cam, and a holley stealth ram intake.

Do the TBI and TPI car's use the same computer?? Do we need a TPI ECM or will a chip change work?? What about the harness?? any sensors interchange between the TPI and TBI??

Thanks for any and all help fellas, this is going in a 5 speed car also just to let you know.

 

Ttt

 

Dude, you're taking on a major project here, and it may be easier and cheaper to just sell the TBI car and buy a TPI version.

You can use the older rear 2 piece main seal if your TPI unit is an '85 or '86, because the bolt hole angles are different from '86 on the intake manifold. I have also read that the bolt holes on the TPI from '86 and up cars can be reamed out and used, but I have never seen it done and I personally wouldn't do it half-assed like that myself, but to each his own.

I don't see the Stealth Ram really complicating anything, excepting of course the issue above with the intake manifold bolt angles. I'm sure if you tell them you're using an older engine they can let you know if it will work. This whole bolt angle thing may be a moot point if you're using aftermarket heads.

I don't know about the Stealth Ram, it's something you'll have to research, but I do know that stock TPI intakes choke off an engine that's trying to make more than 300hp. A bigger Throttle Body combined with the Stealth intake may solve this problem as well.

A lot of the sensors are the same, and I have read that you can actually even use the same wiring harness if you have the patience to read through the factory electrical diagrams and figure out where each wire goes, etc. You'll be missing a few wires but that's a lot easier to add than an entire new wiring harness. However, if you have the factory harness for the TPI, and it's from a relatively same year of car, you KNOW for sure the wiring will be right.

The ECM from the TBI should be the same as the TPI, and a new chip should be all you need. However, you'll probably have to buy a custom chip to handle your upgraded motor.

Good luck man. I did a TPI swap into an older vehicle that was originally carbeureted, and I know I spent more time threading through wires and reading diagrams than I spent actually fabricating the mechanical part of the swap in. At least by starting with a TBI car, all the holes are there and in the right places regardless of what harness you use, the ECM has a place to be mounted, etc.