I have a crate motor that dynos at 425hp and im having a hard time finding a throttle body that will flow enough air and fuel for that much hp. Any help would be great. Thank You

 

Id look at the ported 454TBs or maybe one of the Holley units.

Maybe even dual TBs?

 

I would consider a port fuel manifold. My choice is a Edel Victor JR(single plane) with a 4 barrel TB unit of choice(Edelbrock/Accel). Choice on ECU is the EBL modified to allow MPFI.

 

Fast355 built a 500+hp 5.7L that used a stock 2 inch bore 454 TB, and he said that he didn't have any noticeable manifold vacuum at WOT, so the throttle body wasn't a restriction. Your 425hp combo would be fine with an unported 454 TB.

https://www.thirdgen.org/forums/tbi/...i-reality.html

 

90 lbs injectors at 30 lbs fuel pressure at 80% duty cycle at .45 BSFC will flow 113 lbs and support 402 HP. Seems cutting it close on fueling. VAFPR will reduce the fueling at idle and off idle but I suspect overfueled there.
I feel port fueling a better fit ...

 

I have a set of the 90lb hr injectors,If your interested.

 

It will only take 25 psi for 90# injectors (135 lb/hr) to flow enough fuel at a 0.50 BSFC and 80% DC to generate 430 hp. I have run TBI injectors down to .7msec at idle with good luck.

FWIW, I calculated that it only takes 17.5 psi with 90# injectors to support 425 flywheel hp. Thats running a .45 BSFC and 85% DC. I usually consider TBI injectors maxed out at about 90% DC.