I recently purchased a 1990 Stingray SVC 200 with a Mercruiser 350 Mag Alpha 1 and I can't find out the horsepower rating. The title says 230 hp but that seems a little low because it has a 4 barrel Rochester Q-Jet carb with thru hull exaust. It runs about 52-55 mph on the gps with a 23" pitch...