thorpe991

So right now i have a 87 with a tpi 305 in it the body is rotted but has low miles on the drivetrain so i bought a 86 body i plan on swapping over the trans an motor but i want to get rid of the tpi an most of the electronics on the motor. I wabt to know could i buy a tbi intake for a 305 and have it fit the stock heads? I know that gm in 87 made the heads of the tpi engines diffrent than 86 an prior

thorpe991

When i go to summit racing.com an go to intake manifolds for tbi it akips thw 85 86 87 years in selection it goes from 84 to 88

Schurkey

Far as I know, all the iron heads from '86 to '95 (center bolt valve covers) have the same intake manifold mounting face. If I'm wrong, I'd like to know.

'85 and older (perimeter bolt) have all the intake manifold bolts installed at the same angle. '86--95 have the center two holes at the goofy angle (except aluminum heads.)

What "electronics" is used on the TPI that isn't used on the TBI?

8t2 z-chev

it was 1987 model year the heads changed to centerbolt with the center intake bolts straight down-the block did change to 1 piece RMS in '86

Schurkey

Thanks for that.

Putting a newer manifold onto cylinder heads with the older bolt angles is going to be...difficult. Going the other way requires little more than oblonging the center holes in the manifold, and using wedge-shaped washers.

thorpe991

Im not sure but i did a 350 swap on my old truck that had tbi and hooking that back up there was barley any wires ones for injectors ones for alternator and that was about it so thats what i was hopeing to get back down to and i was looking at summit again and didnt put in the modle just engine and a whole swap kit to make a tbi/tpi engine into a carbed engine for 86 to 93 poped up so i might go that route and ditch efi all together

Schurkey

Hint: The TBI needs the same sensors as the TPI, although they may be located in different places. One exception might be the MAF sensor, which TBI doesn't use, and of course, there's only two injectors instead of eight or nine.

Enjoy that carburetor.