Hi Tony,

No, I haven't really done much in the way of header testing myself. I had a set of Stahl headers custom built for my dyno testing and I use them on every BB Mopar that I run on the dyno. I suppose on the big dog motors they cost some power and on the budget motors they cost some torque.

As far as your motor is concerned I think you're right in the ballpark with the numbers. Rather than spending anymore money testing on that dyno if it was me I'd haul the motor to a dyno where you have some other verification numbers. I'm not sure how far CRE, Hughes, Best Machine, etc are from your place but if you got it on one of their dynos then you could compare apples to apples.

My guess is that you have a nice solid engine design but the dyno is off a bit. I could be wrong though as maybe the dyno is working right and for some reason the motor just isn't making the power one would expect from that combo. Hard to tell from 2000 miles away!