I finally decided to repack my D&D can. As it was incredibly loud. So loud in fact, that people who rode several bike lengths in front of me said that it was fuccccc'n loud!
I lined the the core with bronze (6) bronze wool pads.
Then, wrapped it with 1" thick industrial furnace fiberglass insulation rated at 1200°F, until it reached the inner diameter of the sleeve.
Next, used masking tape to secure that layer, and made it very tight, so as to compress it down as much as possible.
Then covered it one more time with the fiberglass insulation, then taped it again.
The can had so much insulation on it that I had to shoehorn it in as I slipped the sleeve on. It weighs a couple of pounds more than it used to as well.
Result:
Unbelievably quiet!! At start up and idle she just has a deep throaty snarl, but not even loud enough to scare my 2 year old little girl (who used to scream and run when I started it in the past!). I cannot hear the exhaust at all at steady throttle on the highway while driving at about 80mph! But still very authoritative, and deep sound when gettin on the rev's! I love it, I can even here the light whine of the drivetrain! God, I wish I would have done this sooner!