I purchased a 2012 Tri Glide a couple of years ago with an unknown brand of slip on mufflers. They are fairly loud which is ok with me but my wife says they are louder than need be from where she sets. I have noticed on Facebook, and other social media marketplaces, people have take offs from their bikes which are new or nearly new, at very low prices, and have swapped for aftermarket mufflers. Does anyone know what Harley touring models will interchange with the Tri Glide? Is there a part number/model interchange book or chart available? The marketplace ads sometimes have the OEM part numbers and sometimes have the model it came off of and there tends to be a butt load of pipes to choose from. I am looking to return it to factory type slip ons. The later models I have heard have had a nice mellow tone to them.