87 IROC Z 305 TPI setup on 72 350

[mocwon]

I recently bought an 87 IROC with a 305 TPI and auto overdirve tranny. I plan to replace the carb set up on my 350 72 GMC truck with the TPI system from the IROC. I will also use the auto overdrive tranny out of the IROC. Has anyone done this that can lend technical support and maybe an e-mail address? I am thinking about using 24 lb/hr Bosch style injectors and use a Painless Wiring harness. Any help would be greatly appreciated. Thanks, Greg

[Dean23]

sounds like a wicked upgrade. keep us posted on how it runs and how the change over goes

[Longhorn Man]

You'll want to upgrade the throttle body too, you'll be feeding 45 cubes more.
I would look into spending some good money on that 700 before slapping it in there. They are known for falling apart.
Also when installing it, get the instalation kit that includes the oil pressure guages, don't just adjust the TV cable per Chilton's instructions. It does more than just kicking down the gears, it also regulates the oil pressure.

[dtlilly]

I recently bought a TPI set-up from an 86 Iroc with a 350 (intake and all wiring/computer). Then I found out I needed to use TPI heads as well, so I sold everything at the Super Chevy last weekend.

I don't know if that is the same in your case.

[Mike C]

The 85-86 TPI setups, and all of the aluminum head Corvette TPI setups, use the regular 69-86 bolt pattern. 86 used centerbolt covers with regular intake pattern. The 87 and up TPI setups on the Camaro have the center intake bolts at a different angle. It is possible to slot the bolt holes and use it on the older heads.

The throttle body is not a source of restriction, at least early on. What you do need is a set of 22 # injectors from a 350. Stock LT1 injectors are a good choice for 350 TPI motors. IF you are going to buy new, Ford Motorsport is the cheapest, with Accel not far behind. About $225 a set of 8.

If you are going to have to buy an intake, check out the Vortec TPI intake that Scoggin DIckey has and go ahead and upgrade to Vortec heads when you do the TPI swap.

[smokekiki]

Check out www.chevythunder.com lots of info.He also makes wire harnesses cheap.Comps and chips too.You will need to decide if you want to keep the mass air flow,or switch to speed density.Speed density is less complicated,mass air flow is more forgiving when making mild cam changes and other performance changes.You can redo your harness or have chevythunder redo it.I got one of his harness and computers.Works great.175 for harness.