I believe the 1 on the right is easier to alter your transfer ports since there open. Idk power wise between the 2 cylinders. Also I'm not sure if you got a high hole piston or a low hole piston will depend on what cylinder you need. I'm sure some1 can explain or recommend a cylinder. I like the steel sleeve cylinder for longevity & the torque it makes, plus it's not slow by any means. I top out at 38mph or should I say I chicken out at 38mph cause the walmart bike feels like it's going to self destruct.