Prop advice... need more stern lift... Add hydrofoil?

[spareparts]

generally speaking, the higher up you can run the engine, the more efficient it will perform, but with everything, there will be trade offs. Easy way to check it, have someone run the boat in a normal fast cruise and trim position, look over the stern and see if you can see the anti-ventilation plate on the engine(the thing you bolted the fin to). It should be just out of the water at a good fast cruise and proper trim position. The fin should be skipping across the top of the water. Be careful, don't fall in. If you have time to play with it, raise the engine up till it blows out in turns then go one hole back down. The higher you raise it, the less leverage you will have