I've been trying to find the right prop for my 2000 23' deckboat, 5400 lbs fully loaded, 5.7L Volvo Penta, 250 HP. Most of my playing is at high altitude, 5800 ft and above, and I get pretty good results with a 15X17P 3 blade alum. I also tried a 14 1/2X19 3 blade alum, but it didn't give me...