Prop selection is voo-doo magic that's why I have more props in the shop then my LHS does
I know tach readings are fun and all but you really need to fly a prop to know if it's any good
I have had plenty that didn't seem to work good as fans but sure fly sweet once there unloaded
with so many different planes flying with different type wings there is no way to know what prop will fly well without a test flight or two
ay least that's what I have found trough trial and error