When I had drag pipes on a Big Twin I use to make baffles all the time.
find an exhaust adapter that the largest diameter of it will just fit inside the end of the pipe. Then some exhaust pipe that fits inside of the small end of the adapter. 6" for each baffle. tack weld them together. cut eight "V" shapes in the small pipe like what would be made by an old can opener. 2 at 0-360 deg. 2 at 90 deg. 2 at 280 deg and 2 at 270 deg. take a punch and bend all the "V's" into the pipe at 90 deg. to the pipe. slip your creations into the tailpipe (small end first) and when they're a couple inches in from the end drill a small hole on the uncerside through both the drag pipe and the fat part of the baffle. install a sheetmetal screw in the holes. You're done. Baffles are installed.
