diggs83TPI

hey i have a 85 TPI that just went to hell on me ... spun a bearing ... any who... it has a 305 TPI Set up and i cant find anything to jus put in right now but how ever i found a 1988 chev truck 2wd with a 350 BUT its not TPI its TBI ... now could i use the engine ? on Stock computer ? and jus Swap over the fuel system i want to keep it tpi ? im jus trying to fully understand .. ppl say i CANT use the computer and the car wont run right ? some ppl say it'll run fine .. some one said i Could not use the tbi heads on the tpi .. whats the difference between the TPI and TBI heads .. any thing ? i cant find any engine's locally .. and with a tight budget ... right now im not looking for power jus to get the car running to get me back and forth to work any help would be great thanks

ljnowell

You can use the tbi heads, but you dont want to. Take your 305 heads off, and put them on the 350. Run all of your tpi stuff. If you read the 305 to 350 swap page above, and go over to the tpi forum and read there, you will see that this is all to easy. Yo umay want to put bigger intake valves in your heads. Without it they will probably still perform as good or better than the tbi heads. A search would find all the threads you need and all the info.

five7kid

iTrader: (14)

I'll expound a little on ljnowell's response. The '88 truck heads have what are referred to as "swirl" intake ports. The factory incorporated them to improve low-RPM efficiency (and to some extent emissions). However, they produce a restriction that hampers performance when valve lift exceeds about .4", and RPMs exceed about 5000.

Now, that probably isn't a big problem with TPI, because TPI has similar limitations. But, you'll have one additional problem, and that is the '87-up heads have the center two intake mount bolts at 72 degrees instead of 90 degrees like the rest, and like all of yours are on your '85 TPI base. You can solve that by trading someone for a '87-up TPI base, or, like ljnowell said, use your 305 heads on the 350.

The '85 TPI won't be bothered by the increase in displacement from 305 to 350, but the bad news is the '85 TPI ECM wasn't their best effort. If you can find an '86-'88 TPI ECM, that would help a lot, and if it's an '87-'88 350 ECM to boot, even better.

diggs83TPI

So i CANT use the heads ? or the ECM ?

five7kid

iTrader: (14)

You can use the heads, and you can use the ECM. The only question is the results (well, your TPI base will have to have the center two mount bolts holes on each side modified). Stock cam, 350 TBI heads, stock TPI, stock ECM, it'll run okay. If you decide to go with more cam, that's when things are going to start snowballing on you.