These are early R100 heads with 38mm exhausts and 42mm inlet valves At some point there was an issue removing the exhaust nuts hence the thread damage,( I took them as cores) I've thread filed the ugly one and torque tested them and they are good. one is uglier than the other but it is mostly on one area and a nut threads on fine and torques up fine. These have new seats and new intervalve (OEM for F650) exhaust valves, They look like they had exhaust guides recently as they measure up unworn. They've been Vapour Honed to give a nice easy to maintain closed pore finish. Please ask any questions you may have. I can replace the exhaust thread for an additional 75.00 if you're worried about it but there really is no need it is mechanically sound.