I moved my 50hp Evinrude to my 18' Sylvan Sea Master. It is about 600 pounds heavier then my smokercraft. I currently have a 11 3/4 x 17 prop on it now (which is stock). It planes at 20 mph and tops out at 26 mph. What prop would I need to get a better hole shot and a couple more mph top end. I have no tach but it seems that the engine is running at a lower top end rpm. I was thinking a 13 pitch....... What would you recommend?