I ran 34mm PJs on my 350cc motor with CPI's Huge gain. Sell you the complete bolt on kit from Billet intake to K&N's including throttle cable $350 to your door. Or I have some stock bored out carbs too about 28mm. You won't see much of a difference going from stock to 28-30's Kinda a like doing a budget boost on a jeep. it is really just a tease