I had two choices, 8 1/4x 8 and 8 1/4x 8 1/2. I ordered the 8 1/2 pitch. The motor is pushing a 14' Sea Nymph semi-v, it's a very lightweight boat, not sure of the model. I'm using it as a duck boat, so at times I've got several dozen duck decoys, shotguns, shells, two guys, and a deep cycle...