I have a 1985 Honda ATC 350x. I am having a Powroll 368cc big bore kit put on it, which includes 10:1 compression; there mid range cam with .355” intake and .360” exhaust lift. I have a new 4" diameter SuperTrapp racing exhaust and new 300EX 32mm carb (which was recommended by Powroll.) What would be a good gearing combo for this ATC? I run 20" Holeshots on the back as opposed to the stock 22" tires. The stock gearing is 13-tooth front, with a 40-tooth rear. How many disks would be appropriate in the SuperTrapp pipe considering this setup? Also, does any one know a formula for checking the approximate top speed based on your gearing and other engine/ATC info? The stock dry weight was 320lbs. Does any one know the percentage of horsepower that is lost between the crank figure and the rear wheels? I know the crankshaft horsepower, and I would like to approximate the rear wheel horsepower.

Thanks for any help that you can give.