72F air temp, 10/20 fuel, Enya 3 plug, new crank bearings.
13x4W APC - 10,200rpm peak, 1,500rpm idle
11x5 MA - 12,330rpm peak, 2,300rpm idle
11x7 MA - 11,700rpm peak, 2,300rpm idle
12x6 APC - 10,440rpm peak, 1,850rpm idle
The 11x5 is probably too small for flight due to prop unloading, but the carburetor reversion was zero on all props but the 12x6. Using a little more nitro may have helped with this as well. No knocking or pinging, lowest idle speed noted was 1,250rpm but it wasn't stable. Fantastic sound at that rpm though.