On my berrien, I have an EMPI Exhaust (see image below). Can I connect some other muffler to the "end" of the spring loaded connection thats less noisy? Sometimes we just want to cruise and talk.......and cant!

I have seen some people add motorcycle mufflers but I can't tell you about the noise. I have used the "Quiet One" on the last buggy (and will be on the Deserter) and it was very nice.

Where are those sold?

CB Performance

I have an original Manx Sidewinder with a Camco Fab muffler capped off by a Super Trapp spark arrestor. It's nice and quiet with a throaty growl.

How does that attach?

I bolted on a 3 bolt collector then slipped the muffler over the collector and fastened the muffler with a band clamp. There is also a clamp around the body of the muffler that is bolted to a tab that I TiG welded to one of the tubes.