Dump that stupid D&D muffler, put a stock muffler back on it and ride the piss out of it. The noise of that exhaust will tire you quickly.
I see the 16.5" Showa recall shock on it. They die. You can get them rebuilt but, that's false economy on the 16.5" Showa.
You can often find the 14" replacement shocks on Ebay (new). You need the updated front mount to install them. Sometimes, they are bundled together as leftover 'recall kits'. It's also a Showa. Not perfect but, the best of the later factory shocks.
It makes so much torque that I often forget that it makes power above 4500 RPM. Hate to tell you but, it's not going to cruise at 100 MPH for very long. 101 HP just isn't enough for that and you'll be wound out to get past the century mark; it happens but, not very briskly. It doesn't matter. It's brilliant between 40 and 80 MPH and that's where most sane people spend the most time.