Ok I have had my 86 IROC since I have been out of college (1990ish). It has the 305 TPI engine with about 160 to 170,000 miles on it and needs some MAJOR work done.

I want to put a 350 in it. What are my motor options? I mean can I just go to the junk yard and grab one or does it need to be out of a "like" car or what years work, etc.

I would also like to keep the TPI due to I have invested money in upgraded parts for it but would like to get at least 350 hp for the car. Do I need to change the whole ECM or just the PROM or will mine work ok? Some have said in threads here that you can get the ECM re-programed but I don't know where or what to do.

Now before I get "harped" on I have done searches on the forums and spent all Sunday afternoon reading like posts but didn't find very many answers to my questions. So I guess I basically just need to know:

1) What kind of 350 will work
2) What about my ECM/PROM
3) What do I need to do to use my TPI
4) Any other items I may have forgot...

Thanks

 

I'm not going to hit on all your questions, but I'll tell you about getting a 350. First, since you're getting an engine anyway, are you sure you want to assemble one rather than just buy one? Second, While you can use a pre-'86 350 block, with matching oilpan and flywheel or flexplate, it would be better to start with a newer one. '86 was the first year of the 1-piece rear main seal. The engine does not have to come out of another Camaro/Firebird. Aside from the main seal related stuff, '87 was the first year of the rollers on the lifters. This is desirable. And while the '87-'95 pickups did not come with the roller lifters, the blocks do have the provisions for them. Still, you can just go to the salvage yard and grab any good 350. Don't get the heads, just get the short-block. And if you buy one with pistons in it, be sure they dont have the number 60 stamped into the tops of them. This would indicate it can't be rebuilt again. It might be useable if there's a good crosshatch in the cylinders, but it's still not the best. With your TPI, you do not need 4-bolt-mains. If you get them without having to pay extra for them, fine, but you do not need them. A more ideal find would be a Vortec 350, with the heads, from a '96-'98 fullsize halfton pickup. This would require you to change your lower intake, but if yours is still stock you'll hafta change it anyway, to reach 350 hp. The Vortec heads are good enough to get you there. SDPC offers a crate 350 with these heads and the GM "hot" cam that makes 357 hp with Edelbrock lower intake and runners.

 

wow that's a lot of great info...thanks!!! So pretty much either buy a crate or get a vortex 350 from the salvage yard...right?