I remove a SS 14x3/8 x 19 only going 3000 to 35000 rpm, I install a 14.8 x 17 aluminum it is a 15 spline prop 3 blade
Remember I am restoring this boat I have no base line to work with , Please see
www.nymack66.com for some photo etc , I am stump in regards as to why the engine is not giving me the RPMs everyone is talking about !!