[FUNFER2]

Matt,

On the chassis dyno, I think you're expected HP is a little low.
This equation is for the "Mustang" chassis dyno of 28%.
(Dynojet is apx. 8-10 %)

The apx. loss is around 28 %, with a manual gear box.

554 HP (-) 28% = 398

Assuming,.... your motor needs more fuel, and proper tunning on the distributor & fuel, it should be over 400 RWHP.