You might be able to overdo it!
This is probably a good way to go for a lake boat, but where you may have to motor in significant waves, it would be possible to dunk the motor. Just to show how far some will go, I saw a sailboat in the boatyard the other day, about 32 feet, that had a 175 hp.(yes, 175 hp!) outboard mounted on an obviously added mount like an offshore power boat. didn't see it move, but it should be interesting if he uses all that power! who cares about hull speed if we have gas!