jetting on big bore

[450ex]

let me describe my bike first
i have the athena 480 big bore cyl and am using a mysto cam
i am running a fcr carb off the dirt bike and a full crf ignition
i also have the esr air box replacement(open filter)

just wanting to know where to start on jetting
i am roughly about 1000ft above sea level.

[450ex]

no thoughts

by the way i run vp c12 race gas

no rough figures?