take 2mm off the botom of your 760 cylinder and cut your domes 2mm into your head, then bore it to 85mm and you have a good hitting 771
I started a 760cyl build with this in mind. Only prob is when you de-sleeve, and cut the bottom of the cyl to lower exh port timing you also move your intake ports down 2mm so they would have to be ported/raised the same 2mm to not loose intake duration. prob withat is raising intake ports 2mm = water jackets..
Stick with the X cyl dood. They can be made up to 828cc with bore mods alone. 760cyl for cheap cc's is a bad idea IMO.. For freestyle brap that is.
Now if you wanna do 55 on your ski than by all means 760 awaaaay
I've wasted time and $ on it, and have since gone back to an 83mm X cyl project..