I have a Bayliner 2858 Ciera w/ 350 Mag MPI Bravo II. I cruise at 20 mph @ 3600 rpm yet the Bayliner brochure lists 25-26 mph with the same engine and a Bravo III. The boat weighs about 8200 pounds. My question is whether a Bravo II can make that much difference in cruising speed. Thanks.<br...