Hi, I am trying to line up all of the parts to complete a pair of McCulloch 99 rebuilds. I need a couple of Head Gaskets (pn 24057). Alternately, I created a CAD drawing to cut one out on a CNC router, but I need to determine what alloy aluminum is appropriate. The thickness at the outside is 0.040", and it compresses to 0.035" between the cylinder and the head contact area. I assume that I need a soft alloy vs 6061, and looking for a recommendation.