I have a 2000 21 foot bowrider with the 5.0 EFI Mercruiser and the Alpha outdrive. I currently have a 14.5 19 pitch stainless 4 blade prop on it now. With a light load and calm water, I am only able to get 4000 rpm and 41 MPH at WOT. I believe I should be around 4600 - 4800 for my WOT. If I go...