Ive done the free mods on the 02 wr426 except the exhaust cam timing mod. I ride trails, not tracks, woods, not desert. I would rather not open up the top end and do the mod and then be dissapointed. What about the wr450 cam upgrade, or a yz450 upgrade? Pros and Cons ? Need the INFO! Is anyone sorry that they did the yz timing or the 450 cam upgrade? Let me hear you! THANKS !!!