Gm Tbi Vortec Heads On A Sb 400? Help

jeepinnick · Dec 23, 2008

HE IS MY PROBLEM I WANT TO RUN GM TBI ON A SB 400 WITH VORTEC HEADS, I WAS TOLD... THAT IF I RUN THIS SET UP THE MOTOR WILL BE
A TIRD.. NO POWER, FALL ON ITS FACE ANYTHING AFTER 4 GRAND. IT WILL HAVE NO POWER. IS THIS A BAD SETUP, WOULD IT BE OK TO RUN THIS? WHAT ARE MY OTHER OPTIONS BESIDES A CARB AND EXPENSIVE MULTI PORT INJ. I DONT KNOW WHAT TO DO

I HAVE A REBUILT SHORT BLOCK 400 TO START WITH
THANKS

Brian H · Dec 23, 2008

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jeepinnick · Dec 23, 2008

sorry work program i use, it is all caps

Binder · Dec 23, 2008

It probably won't be a high RPM screamer. Vortec heads are low RPM heads for a 350 and when you put them on a bigger engine it gets worse. Also using a GM TBI on a 400 will almost certainly have to be tuned. I think if you choose the right cam that combo could make descent power at lower RPMs.

Not Jobless · Dec 23, 2008

Brian H said:
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I'm still laughin over that pic :haha: :haha: :haha:

jeepinnick · Dec 23, 2008

IM JUST GOIN TO SAVE UP AND BUY MULTI PORT IT SOUNDS LIKE ALOT OF WORK THE OTHER ROUTE, THANKS FOR YOUR HELP, ANYBODY WANT TO SELL A EDELBROCK MPI SETUP TO ME?:eeek:

Binder · Dec 23, 2008

jeepinnick said:
IM JUST GOIN TO SAVE UP AND BUY MULTI PORT IT SOUNDS LIKE ALOT OF WORK THE OTHER ROUTE, THANKS FOR YOUR HELP, ANYBODY WANT TO SELL A EDELBROCK MPI SETUP TO ME?:eeek:

Why? It's not the TBI by itself that's causing issues. Multi port will have to be tuned as well.

jeepinnick · Dec 23, 2008

the mpi will be able to make more power? off idle past the 4 grand mark, where after 4 grand with the tbi wont be so hot?:scratchhead: :scratchhead:

Binder · Dec 23, 2008

The MPFI will only be marginally better. You need to have the right combination of parts. It's the vortec heads that are the biggest issue for this combination in my opinion.
You could probably have the vortec heads ported along with running the MPFI or use a big block throttle body with the TBI and maybe have something.