Hi everybody, I want to buy a new pipe and silencer for my stock KDX. I am looking at the FMF Gnarly and the FMF Fatty with a Power Core II. What kind of performance gains should I expect from each of these set-ups? On FMF's website, it says that they only have a Fatty pipe for the KDX 200, will the fatty work as it should on a KDX 220? I will also have to re-jet after installing the new pipe and silencer, correct? Thanks in advance for your help.