I have a 98 220, Rev pipe, air cleaner mod, tuned carb, runs great. What I need help with is the sprockets, I am currently running stock. I think it's 13-47. I want a little more hit on the bottom end, should Ichange the front to a 12 and leave the back or change the back to a 50 and leave the front ? I don't race mx but like to ride the track.