By the way...this bike has 4" truck stacks on it and they are VERY LOUD. Is there any easy way to quiet them down some without replacing them?
If they are truck stacks with glasspacks, you may be able to get longer glasspacks with a smaller bore.
In addition, you can "peel" a set of silencers from a stock set and just slip into the end of the truck stacks and secure with one bolt.
I bought a set of silencers from Ernie at Dragon Exhaust. He calls them "wife pleasers". He charged me $80 including shipping. I haven't actually installed them yet though so I can't report on the results.