I have a 2120 w/F150. Prop that came with it is a S/S or polished steel 14 1/4 x 16 (stamped on hub) doesn't indicate which is diameter, which is pitch. Can only get 5400 rpm wot with it. I've been using an aluminum prop 15d x 14 1/4p that seems to work well. I get 5800 rpm wot and it responds...
