I have a '73, 3.0- 140 motor in my Silverline Comoro 17T, which is running real well, but at WOT and trimmed out it is developing 5400 RPM, which is abt. 800 RPM more than the recommended max. Presently, I have a 15-1/2" diam., 19"pitch prop. , giving me a top speed of abt. 30 mph (gps). I have...