I'm about to replace the rear muffler and tail pipe on my '72 GT. From what I've seen so far all the joints on the original exhaust have clamps and have been welded. Was the welding done at the factory or was this something that the original owner did? Do the joints need to be welded when I install the new components? I'm not replacing the front muffler at this time and would like the option to do so later with less trouble.