Small Block & Big Block Chevy Specific - TBI to TPI

Fairly straightforward. Have a 91 Firebird with a 305 TBI, want to make it a TPI. What all do I need? And yes search is still messed up so please don't respond with that. :jest:

thirdgen.org They will have every answer to any question realated to it.

Thanks.

They don't mention if I need a harness, I guess I could check the discussion forums instead of just the parts list. Anyone know if I need a whole harness, or is it just a different deal that plugs in for the injectors instead of the TBI injector?

You need the TPI harness.

Thanks.

Now replacing the fuel lines, is that up front, or were they different all the way back?

Am I screwed fuel pump wise? I guess if I go TPI or carb I need a different fuel setup?

Thanks.

Now replacing the fuel lines, is that up front, or were they different all the way back?

Am I screwed fuel pump wise? I guess if I go TPI or carb I need a different fuel setup?You will need a higher pressure fuel pump because TPI uses around 43 Psi and TBI uses around 13 psi. What type of tuned port motor is it? I just put an LT1 in my 91 camaro. I sent my LT1 harness to a guy named Dana at LT1wiring.com and he made it a stand alone harness. that made things alot easier for me. Also if you have a TPI engine that uses an electronic transmission you will have to use the tranny that goes with the motor or have the transmission deleted out of the computer. Also Dana does that kind of thing as well as mail order tunes. He helped me all the way thru my install. Good Luck!

Oh and as far as fuel lines go I just used fuel injection hose from the frame rail in the front to the fuel rail. 3/8 feed line and 5/16 return line

You need to change fuel pumps.

You need to modify your wiring harness to be the same as a TPI harness (they are almost identicaly except for injector wiring and one other wire

They are far more alike than different.

You need the TPI harness.

Not 100% true. You can modify a TBI wiring harness for TPI with little trouble. The TBI is a speed density batch fire system with 2 injectors. It is easily converted to TPI/speed density batch fire with 8 injectors. All you do is each single TBI injector wiring becomes injector wiring for 1 side of the engine and you add 4 Bosch injector pigtails. Also you need to change things like fuel pumps, and of course all the hard TPI parts. Another option would be to purchase the Holley Stealthram and convert your wiring. Stealthram > factory GM TPI anyday of the week. If you want any more info please PM me

^ The stock TPI system isn't as bad as some people might suggest. Click Here... (http://www.challengevideos.com/video2.php?video=/2006/event7/06event7_pro10_13.wmv&title=<b>Semi</b>+David+Outten+(1990+Turquoise+Coupe)+vs.Tommy+Mich alkowski+(1997+Sebring+Silver+Coupe)+Outten+moves+ to+the+final) :)

To the original poster, we did many TBI to TPI swaps throughout the years. I would highly recommend converting to an EBL ( Click Here (dynamicefi.com)) ECM, makes the entire process much more easier, and a great deal more tuner friendly from the get-go.... ;)

contact "Dyno Don" on thirdgen.org... he did this conversion for my 92 RS.. he can convert your TBI harness to TPI very easily.. and can also give you a parts list of things you need.. 730 computer with chip, injectors, sensors, ect.

he usually posts in the Southern CA board.. but posts a lot in the TPI and ECM boards..his son Kevin91Z is a mod on that board and is a great tuner..

Thanks everyone. Unless I can get the stealth ram for the same price as the regular TPI parts, I don't think I really need the stealth ram. This is for my moms DD. Its just a 305 with a mild cam, which who knows what the specs on the cam even are. Not trying to go real fast, but would be nice to have the TPI.