I *think* it's a Kerker, but maybe a Vance and Hines, it's stamped on the bracket where the muffler hangs in the rear, but I forget which it is. The exhaust is not much more than a glasspack with one big open tube. I repacked it with stainless steel wool. Sounds great, but pretty hard on the ears after awhile. I would like to replace the muffler with a more modern can from a modern 1000cc sportbike.
The carbs were totally trashed when I got the bike. The seller gave me a the remains of a Dynojet kit plus a lot of extra jets and other carb parts. My guess is he never got it right and then just let the bike sit for years out back under a tarp. I did a total tear down, dip, all new o-rings, floats, fuel seats and needles, etc. The jets and needle settings took forever to make work with the pipe and pod filters. Carbs must have been off and on the bike at least ten times, but she was running pretty sweet yesterday. Still need some minor tweaks.