I recently picked up a Formula 280 with twin 5.7 merc's with Bravo III drives. Boat has 26 pitch props and at the lake today for its maiden cruise at altitude (5500' temp about 85, density atlitude about 7000') max RPMs were just under 4k. The range on these motors for max is 4400-4800. So I need to pick up about 600 RPM, should I drop to 22 pitch props? Do the BIII's act like single prop drives where you pick up 100-200 RPM per inch?