Pic should give you an idea. FWIW: Plugging (welding) the other conduit opening close added $ and wt. someone mentioned that meta plugs are available for that purpose. If I were to do another, 1) I would try to put the cover plate on bottom vs the back.; 2) use steel brake line for the compression tubes. If memory serves the muffler bolts are #12. Impossible to get locally. Noise is not a big problem here so I'm playing around more now with exhaust 'deflector' vs muffling.

Latest silver sodered and JB weld tubes fell out of muffler this afternoon with just a few minutes run time. Soder just melted both surfaces showed good soder job just too much heat.