First of all, I spent an hour reading through searches and still have questions so here goes: This project started as a 305 TBI to TPI swap in my son's 88 Camaro. The Camaro has been sitting inside for 4 years and ran fine when parked. Found a donor TPI and pulled the TBI etc off car. Decided to pull the 305 for easier clean up of engine & engine compartment. As long as we had the 305 out, figured we'd pull the heads and have a look. We found there was a coolant leak in #8 cyl. which had caused corrosion of cyl wall while it was parked. Ran a hone through it and it still has some pits that make me think it would need to be bored out. So here are the questions: seems like $ spent to bore the 305 would be better spent on a new/rebuilt 350. Do TPI systems interchange between 305 and 350? Which year 350's will bolt up to the 88 trans (700R4?). We know about changing fuel pump & fuel lines, what else needs to be swapped to go to 350 TPI from 305 TBI. Also, I assume the computers are different for 305 vs. 350?
Thanks guys!

 

Welcome aboard thirdgen.org.

I love father/son projects. Make sure he does the majority of the wrenching...

Yes, a 350 makes more sense than spending machine shop money on the 305. The TBI heads are terrible, anyway.

Any 350 from 1968 to 1999 will bolt to the TH700. The only difference is in 1986 the way the flexplate mounts to the crankshaft changed (with the change from 2-piece rear main seal to 1-piece), and you can get the proper flexplate to mount to the engine and connect to the TH700 torque converter.

But, I'd still recommend an '87-up 350, just because of roller lifters.

305 and 350 hardware was identical except for the flow rating of the injectors, and the knock sensor. The computers for any given year were the same, but programmed slightly differently from 305 to 350.

What year is your TPI? Also in '87, the angle of the center two intake mount bolts on each side changed as well from 90 degrees like the rest of the bolts to 72 degrees. Except on Vettes - for whatever reason, they didn't do that when they went to aluminum heads midway through the '86 model year. Since TPI came out in '85, there were 2 years when the bolt angles were the old all-90 degree pattern.

TPI and TBI fuel pumps were different, but (as I understand it) the fuel lines going to the engine compartment were the same up to the flexible lines. You apparently already have that in hand.

 

Hi five7kid,

Thanks for the reply. Ya, father son project is a hoot. He's 28 now and lives and hour away but he still gets back to wrench. We started this project 4 years ago, then my divorce happened and with moving and finding a new place we're just getting back to it. If we had found the coolant leak 4 years ago we probably wouldn't be looking at cyl corrosion. Oh well.
If I remember right the donor Tuned Port was from an 85. We already have the tank out to change pumps. So the hard fuel lines are OK? Just have to change the flex lines under the hood or do we need to change the rubber between the tank and the hard lines too? Right now he's leaning toward boring the old engine because it will be cheaper and the numbers will still match, we'll see. It's his car and he's an adult. I told him I'd chip in on cost but he still wants the original motor. Thats cool.
Different injector pressure? I think the old ones are shot anyway so we'll have to spend some bucks for new ones, ouch!
As far the computer we just need to have it reprogrammed?