The rule is thatwater exiting the bottom of the hull, when on the plane should not be flowingover the top of the anti-ventilation plate, but just below it, this reduces drag onthe lower unit. When the anti-ventilation plateis in line with the very bottom of the hull, this is Standard. The engine can be raised 1 in.above standard for every 10 MPH above 40MPH. For every 12 in. the outboard is behind the transom (such as on a motor extension mount),the engine can be raised 1 in. above standard(standard being that the anti-ventilation plate is in line with the bottom ofthe hull.)
If you can set it up to comply by these "rules" then it will work. If not, you have three options - (1) get a 25" lower unit, (2) install a jack plate that will raise it enough, or (3) install a motor extension that will allow you to raise the motor to specs.
