Kinda stumped here, recently Did heads and cam on my 99 ls1. Ms3 cam with a 113 lsa, ported pro comp 225cc heads, ls6 intake, longtubes and other small bolt ons. Car put down 337whp???? And made a 12.9 pass with radials. I've seen other h/c cars put down wayyy better numbers than that. I double checked pushrod length and it's good, I've had the tune looked at and it's fine. I just can't figure out what's going on.

 

Is the car a 6 speed or auto? If its an auto do you have an aftermarket stall converter?
Was it on a mustang dyno?
What was your trap speed?

 

It's a 6 speed car, 4.10 gears, trapped 109

 

Hmm. I don't know anything about those heads Is the cam installed correctly? Leak down test? That car should should trap atleast 118

 

A leak down test is my next step.

 

What Rpm were your peak hp and tq?