Thanks Jerry. I have not yet torn down the heads. While cleaning the dust off(they have been on the shelf a couple years) I noticed the two inboard exhaust valves have what appears to be the guides slipped down to the valve head. Never saw that before. Have you? I am fairly well equipped here and could do the guides with a bit of instruction. Still, I have to dis-assemble first and try to figure what caused this to happen. Will keep you posted as to what I find out.