John,

Strange how low your rpm's are, but at least the flying perfomance is there.

I just tach'd mine again early yesterday:

7800 rpm (needle valve slightly rich). Peak is 8,000 rpm.
Using an APC 20x8
L1 plug
5% PowerMaster Fuel
85F Air Temp
approx 69F Dew Point (before the rains came...)
Bison Pitts Style muffler

I'm not sure of the volume differences that you mention, but I'll check for you tonight.

When are you flying that plaen. I would like to see it fly. Ben