I own a 2008 FXDF Dyna Fat Bob. Were you wanting to know about exhaust mods? All I did with mine was buy the full Vance & Hines 2 into 1 performance system. I chose the color black. I think J&P cycles may have them, but I always prefer to use Dennis Kirk for aftermarket parts. They are cheaper than J&P Cycles. To handle the fuel/air system, I use a Cobra Automatic tuner. It works great and stays with the bike forever. No matter what you do to increase performance, the Cobra tuner will adjust automatically. If you have any questions, send me a message.