Jack21:
Burns Stainless offers an alternative to welding the mufflers. They offer a quick release, no bolts/nuts, V clamp and flange assembly. The flanges are welded to the extensions from the primaries and the muffler and are secured by the quick release V clamp. Allows for changing the muffler or running open pipes with a minimum of effort.
http://www.burnsstainless.com/
Don