I own a 1998 KDX 220. It is all stock except for a new rear tire and Boyesen Reeds. For christmas I'm buying a gripper seat cover, twin air filter and some other stuff for it. I ride woods and I want to know what the best mods are for a KDX? What would be better to get if you want more power, A FMF powercore silencer, or a FMF Gnarly pipe?