Serowbot and I installed a Harley Davidson muffler, part # 65844-95 USA Catalyst, on my 2003 last week.  We rejetted to 150 from the original 145.  Muffler slid right on with a shim cut from a Campbell's soup can and clamp from the Dollar Store.  Bolted straight up, one bolt only as the muffler is too short for 2.  Looks good, sounds great and seems to go a lot better.  Must have saved about 15 lbs in weight, the Savage muffler weighs a ton.