I wanting to buy the Michigan Wheel Inc. Apollo seris stainless prop for my 2001 Four Winns Horizon 190 w/ Volvo/Penta 5.0L. I think stock is 19p, but I will be towing knee-boards and 4 person intertubes. So do I stay with 19p or what would you suggest? I hit about 44ish...now and want to go maybe a bit faster... 