changing carb to a t.b.i or tuned port injection


Junior Member
i have a `86 gmc 4+4 im replacing the engine with a new gm long block 350. truck has a 700r trans.
my question is how do i go about putting a tbi on my truck engine?do i need a computer for the tbi?
is also possible to put a tuned port injection on this engine and what is involved to put this on?


2000 Club Member
The easiest way to convert is to find a donor vehicle and swap all the parts, it gets cost prohibitive otherwise. Holley and Edlbrock both make aftermarket kits to convert from a carb to EFI, this is an option too. Each type of injection system has its own unique computer and harness.

I looked into converting my TBI 454 to port injected and it's too big a project to make sense on my truck. Not only would I need the manifold & injectors, but also the harness, computer and related sensors as well. A major undertaking for a work truck.


Junior Member
central NY state
You'd need all the sensors, wiring harness, computer, and fuel delivery system (in tank pump, fuel sender unit, etc.) If you've really gotta have EFI, either find a cheap but COMPLETE donor truck, or go aftermarket. The first choice is a lot of work, the second is expensive, around $1800 I believe.