Bought a 1988 Supra Pirata. It has the Ford 351, Borg Warner Velvet Drive and 13x13 prop. What should the top rpm and mph be for this boat and motor. Runs up to 3500 at 38/39 mph. That is it. Makes me wonder if a 23' boat is too much boat for the motor. Where can I get information on this. Members help will be greatly appreciated.