My '93 ultra had those flanged type pipes on it. I wanted to also change out the mufflers, and couldn't find any that would bolt right up, so I cut the flange off the header pipe as close to the rear of the flange as I could. The new mufflers seemed to have an ID, just a hair larger then the pipe. My buddy who worked for a muffler shop used a pipe expander ,to open up the header pipe just enough to give it a better fit. The left side needed a little more expansion then the right side. You gotta be patient and go a little at a time cause there's no going back if you expand it too much.,,

 

A buddy that works at a muffler shop!!??? That's something we all could use!

 

I cut the flange off the existing exhaust pipes, opened up my V&H slip-ons and sent them home with a wooden block and mallet. Used the original clamps from the '93 mufflers which worked fine. No exhaust leaks or backfire so they sealed well. Thanks for help guys.