RE: What 3 blade prop for a 46?
Ya' might consider a Graupner 3-blade. They make MANY sizes and is an EXCELLENT performance prop. Probly' have to mail order it though.
APC doesn't seem to be big into 3-blades.
Master Airscrew is OK and they have many 3-blades to choose from, but they're just not as good a prop for performance IMO. The MAS will take a beating though!