I have a 1986 sea ray pachanga rebuilt engune 5.7, alpha one out drive also rebuilt, boat dry weight 3,000 lbs, 63 gal. tank 3/4 full the alpha 1 gear ratio is 1:50 -1 manual says max. RPM is 4200 to 4600 prop #1 j15X17 4900 RPMs 47 mph, prop #2 14.5X19 5000 RPMs 48.5 MPH all test using garmin...