20' Master Angler, Yamaha 115 four stroke

[McGillicuddy]

Your 20' is a bit longer than the originals.
Also as Capt. Terry mention sole and transom were raised.

I think 366 lbs Yamaha is fine. Not sure of its gear ratio, but if 2:1 or so, a stern lifting 13-3/4 x 15 ought to give your best all around performance. Best hole shot, 12-15 mph plane, 4+ mpg at cruise and about 36 mph top end. I really like the Quicksilver Black Diamond in aluminum and PowerTech's MQF 3 blade. I believe they both have a smaller 4 blade variant of similar blade shape.

This will vary if Yamaha has gone to a 2.25:1 or more like Suzuki and others have done. That may enable more prop.