Customer Is trying to build a pontoon boat to haul logs across a river. He wants me to design and fabricate a frame that can with stand 8000 lbs of torque to mount a big winch on. I have never had anyone give me such a precise strength without a print. I was thinking 3"x3"x1/2" angle for the perimeter of the frame and 3"x1/4" for the braces across. Dose this sound strong enough? I've never had to get strength out of alum like this before and I'm not familiar with its capabilities. Anyone have any ideas. Design wise that may strengthen it?