my buddy has a 2000 formula Z 600 he is setting up for 660 drags on ice and was wondering what gearing he should use, he is all stock gearing, motor with some minor clutching and 144 chisels picks on stock .87 track. We were trying it out today on the ice, the way it is now it has good take holeshot and midrange but no top end thats were the other sleds were getting him, the last 150 feet or so. his engagement is 4600rpm can't remember his WOT rpm was but would like some help for up coming ice drags