set of x heads for sale

rotator retainers on the exhaust valves are low RPM truck parts, keeps the carbon buildup on the valve face to a minimum from lots of low RPM idle and use. You can see the difference as they are 2 part retainers. They are just heavy and not a high RPM/HP part, more like a HD part. But they also look to be gasket matched so someone was looking to get more out of them.