Maybe he is throwing in extra HP because your C6 and 9" are eating some power. Your chassis dyno number could be 5-10% higher with a C4 and and 8". Not as strong, however.
Besides, who cares what the flywheel horsepower is? RWHP is what you want. I have a buddy who is a former NASCAR engine builder. He says after a test on an engine dyno, he subtracts 25% to guess on a chassis dyno number and he is never disappointed. You are doing it the other way, but you get the idea...

<font size=-1>[ This Message was edited by: 67VertMustang on 3/28/07 7:13am ]</font>