Im trying to decide on which prop I want to buy and was wanting to know what kind of rpms are you guys running while wakeboarding with a 644,856 or 1578. 21-23mph. I know weight will play a factor but I was looking at a acme 856. I thought the 1578 would make the motor turn to many rpms even though alot of guys like that prop. Right now I have a 14x18oj and rill probably run 1800ish lbs of ballast for a while if that. The sacs can hold 2400lbs'ish. thanks