OK, I read the Sticky. I'll provide all the info I have. 1974 Olympic 19' V hull, bow rider, 1974 Chrysler 120 HP outboard. New tach, set for 12 poles., 13x15 three blade alum prop. also have available a 13x17 prop. Running against the current in intercoastal waterway, WOY tach 3200 rpm...