I have a 18.5 ft. Bayliner with a 3.0 engine with a 14.25 inch, 21 pitch aluminum prop. At WOT I am running at 5100 RPM at around 42 MPH (via GPS reading). The manufacturer suggests WOT be between 4400 and 4800. Does it sound like I need to go to a 23 pitch prop or should I just switch to the...