stick with stock air filter first off. i promise you it will perform better than any other aftermarket filter. there are loads of tests that prove this. also do not buy dynojet, it doesn't mix well with our carbs. factory pro or ivans jet kit will be good. factory pro and ivan have pretty much spot on r/d, call them up and tell them what kit you have with your air intake/exhaust setup and they will tell you the mains/pilots/air fuel mixture to use and it'll be pretty spot on, meaning if you take it to a pro, you'd only gain maybe 1-1.5hp from their base.