Harley's vibrate RIGHT?
These are brass high nuts, U can get them for about a buck or so a piece
They act like a heat sink, and also cover ALL the threads so taking off your exhaust is easier, and less chance of wrecking the threads or breaking an exhaust stud= BAD JU UJ
Torque the new nuts 10-12 ftlbs, recheck @ each oil change. The buggers do @ times loosen up a bit