I bought a 1977 Ranger 1750 Fish/Play. It's the Sport or tri-hull design. Plains out right away, the engine is running at 4,800 trimed down (5,000 is max). Prop is a SeaBold 13 X 19 Stainless. The tilt is not working properly, but i took off while trimed up (slowly to not overrev) and i was able to get 40MPH and spining at 5,200. The MPH was figured on GPS so it's right. Calm water, average to cool air temp, 2 people on the boat, livewells empty, and otherwise lightly loaded (the boat, not me). Any ideas what this hull should run?