I just installed a cast aluminum Clifford cover with the 2-216 hold down nuts on my 261. I used the thick 216 gasket with weatherstrip adhesive on the cover side. The cast aluminum gasket surface is dead flat and will not flex with serious torque on the 2 hold down nuts. I have pretty good top oil volume and absolutely no seepage through the gasket. It also has a PCV tap if you woiuld like to install positive crankcase ventalation.
