I have a 2105 tx 190 with a 115hp 2 stroke merc pro xs,4 inch jackplate,2 3/4 prop to pad, rubex 13 x 19 ss 4 blade,currently running 50 mph at 5200 rpm wot, that's my max,a guy has a laser2 13 1/4 x 20 worked prop he says the prop would turn me at 57mph? Any thoughts