I picked up a set of Screaming Eagle somethin' or others, left opne outside, so that's old news.  BUT, it sounds waaay better than the stock one.  I tried drilling out the baffle of the stock only to have my dad turn on his lawn tractor to compare, and yes they were VERY similar.  So, after installing this Screaming Eagle, a world of difference.  I still need to rejet though.  Also, I just ordered an Old School "Trumpet" Muffler, like the old BSA, Trumps, etc.  Once that arrives, we'll see how that sounds.  Kind of anxious.