hi people i am lookin to buy an italkit 50cc cylinder head for my 2006 rossi rep aerox but not sure if i need a racing crank? i am running leovince zx pipe, polini variator and flywheel,polini reed valve, stage 6 belt, white malossi torque spring with a malossi racing clutch and bell. i will also be looking to fit a 19mm arreche carb with the cylinder but if i put an induction filter and bigger jet in the carb the engine will be fully derestricted apart from the rev limiter but do these still work with performance cylinders? or should i leave airbox on the carb to tame it and save my engine?