need 400ex to be faster

[Hondarider440ex]

I have put a 440 kit in it, with a hotcams stage 2, curtis sparks x-6 full, and wanting to race motorcross but needs to be a little faster and what size gearing should I use.

[Unverfehrt400ex]

for gearing try going down one tooth in the front and running some 18" tires.