the domes are cut for the stroke, domes were cut by joe ham at precision powersports it is a cool head, theses are gas cylinders, will need a new set of pistons and rings, they are big bore blaster sleeves with blaster windows all drag porting done by rudy kurtz and they are 68.75mm never had on a dynobest time i could produce was 4.3 in 300ft. (with 275 lb rider) on a bike set up for me gearing wise so alot more potential is in them. they are also polished. i will email pics to you.