My boat had a piece of plywood attached on the inside of the transom. The transom is an inner and outer aluminum wall with wood core. I'm guessing that the plywood was a cushion so the OB clamps didn't deform the transom aluminum. The clamps had pretty much buried into the plywood and made two round cavities from clamping. I'm wondering if I could replace this plywood with a piece of 3/8" aluminum sheet instead of wood? The OB is only a 9.9 HP and the boat is rated for a max of 20 HP. I'm only wondering if the OB clamps would be able to move on the aluminum because of not being able to bite in. Thoughts?