You could get someone with a tig to fabricate a short reducer from 2" to whatever size, and use the muffler you like. You might even find an adaptor at a muffler shop. I used some stainless thin wall tubing from a swimming pool ladder, reduced from 2 1/2" to just under 2" and cut and fit several pieces of the ladder to give me lots of ground clearance and run back to a stainless flange I made to bolt up a GSXR muffler. Sorry about the pictures, but the bike is apart right now for paint etc.