So here's the scoop. I put a newer 94 motor in my SC. Got everything up and running. Fixed a vacuum leak and everything seemed to be running fine. I was just cruising down the highway not getting on it at all when all of a sudden I heard the valves pinging quite loud. So I pulled over at a gas station and checked my oil. Oil was fine and so was the oil pressure. The check engine light never came on or anything. This was last night around 10pm in 20 degree weather so I really didn't feel like messing with it. So I got it towed back to the shop. Once back at the shop I fired it up and looked under the hood. My #2 spark plug wire was off. I shut off the motor and reached down in there to see if the spark plug was still there. It was but it seemed like it was stripped out. I tried to simply unscrew it but it would not and it wouldn't just pull out either. Does anyone know what might have caused this to happen?