reviving old seacraft (propeller question)

[Fr. Frank]

If the cavitation plate is exactly parallel with the keel line, or the front of the cavitation plate is higher than the rear, you need to adjust your mounting height upward.

Fr. Frank,
Could you verify that for this situation, the motor needs to be mounted higher?

OOPS!! I make a boo-boo. Sorry, guys.

Assuming a transom mounted engine, if the situation is just as described, where the motor ventilates too easily when trimmed, then no, the motor needs to be mounted LOWER.

LOWER LOWER LOWER

This should increase performance AND efficiency. It's about the angle of attack. The idea is to be able to fine-tune the angle of attack without introducing air to the back edges of the propeller blades. How much lower to mount is the unknown. I'd go one bolt hole to start.