Not a muffler but DC has a factory pipe which replaces the cat- sorry I don't have the part number handy but you can get it from
some of the 4" exhaust or muffler threads on the 12v or 24v forums.
------------------
Bill Lins Wharton, TX 98 2500 QC SLT,12 valve,NV4500,3. 54 LSD,Manik grille guard,K&N filter,Amsoil everywhere, Reading aluminum utility body and bumper,Optima yellow tops, silencer ring, cat,& muffler all stolen,
waiting for Psyscotty air