RE: Propellers for Norvel engines
Big Mig .061 should do about 18000rpm on a 6x3 and 10% Nitro. For RC applications I think that 4 pitch is needed or one will only use full throttle. The MAS 5.5x4 is a nice one, so is the cox 5.5x4 (slightly higher load though)
What is the purpose of the original question?