forget about the motor mods, a pipe and reeds will do, GET YOUR SUSPENSION FIGURED OUT FIRST!!! i cant tell you how embarassed some of the kids last year were who had hetric cylinders/240 kits etc, and they were getting beaten by a blaster with a stock motor, i had a rollin suspension setup and tat made up for my lack of motor mods, i got the carb after 3/4 of the season was over, and i made a big difference, but not nearly as much as a proper suspension setup did.