There are no cylinder liners in a air cooled two valve Ducati motor. There aren't any cylinder liners in any Ducati motor actually. The cylinder bore is treated some times called plating but I don't think that is accurate in this instance. The cylinders are bored out and sent to Millennium Technologies for treating or coating. They are just like original cylinders. There is plenty of meat in the cylinder to do that. The place that gets thin is the cylinder skirt that hangs down into the cases. I didn't bore my cases so 966 would be the limit if you bore the cases you need to start with heavier cylinder and you can go out to 984cc.