They are stock cylinders bored and ported by trinity with the head mod done also. I bought the kit from a member a few months ago and they just sat in my garage. I caught a sweet deal on a cheetah cub kit for my banshee so thats what im running now. For as the bore size i said earlier i believed it to be 35 but im not sure its been awhile since ive talk to the previous owner. I could do some measuring so i can know forsure and let you guys know. A new price of 300 shipped i just need them gone.