As I said earlier my 066's cylinder has never been removed which says it's bottom end is still good too.
This 066 had a life of mainly cutting spruce and tamarack lumber with a 36" Alaskan sawmill. Also equally years of bucking and noddle splitting birch firewood, working in temperatures from as high as 110 to -40 below F.
This is a 066 Magnum Artic with the heated carb to keep it running at -40 below, nothing harder on equipment then the cold with snow thrown in

It has a built in thermostat that keeps the carb a constant 77F temperature. Last time I checked this 23 year old saw's heating element still works.