Quote Originally Posted by Greg Amy View Post
The one described as "...over 400whp on a 3.4l stroker s54 that revved out north of 8500. I remember him saying it cost a ton, somewhere near $40k though."? Doesn't sound STU-compliant to me...

All the other non-turbo S54 engines and dyno charts there are indicating 350-ish. At ~3500# sounds like a good STU fit.
That's 350 with stock cams, which are open, and without head polish/porting. The right oe cams and it's another 10 hp, without even resorting to pulleys, or overdriving the two dry sump stages, which are prefectly STU legal.