Only 4500 -4800 RPMS- 90 HP Johnson on 20'SF

[McGillicuddy]

As you reduce your pitch to increase your rpms, you may also want to consider the height of the motor (anti-cav plate in relation to hull bottom), and the shape of the prop. If you're going to change it out rather than have it re-pitched, you might want to check around for a prop that is more efficient with your hull. Especially, since the prop was previously fitted for a tri-hull. Some designs are certainly easier to turn than others and will have varying characteristics.