I'm building my own transom adapter, the plate i'm using for the main peice is 3/16" thick. I have about 3/16" or so clearance around the majority of the pump minus a few cuts for the jetaway ears and what not. I plan on making it modular so i can pull the pump easy. For the plates that bolt to this plate and press up against the pump how thick should they be? I have 1/8" aluminum, it seams fine but if i can get away with 1/16th i think it would look better.