I have a 1979 22' Cruiser with a 1989 5.7 liter merc and a 1992 alpha 1 gen 2 outdrive with a 14X19 ss prop, the boat weight is somewhere in the 3500 lb class. I can get the boat up on plane at 4000 rpms and after up on a plane can cut back to 32/3400 rpms but engine still suonds like its...