Stang went down Saturday Night

I was driving around in the movie parking lot and suddenly the car started making a loud noise that sounded like an exhaust leak coming from where the header meets the head. I popped the hood and found the wire of the 8th cylinder plug was dangling around so I was missing on the 8th cylinder. I looked at the hole where the plug goes in and it's all scored on the outer edge and the threads are torn up on the inside as well.

Anyone have any clue what happened? I hardly get up on the car and I didn't last night when this happened. The only thing I am considering trying to fix it is tapping the head and rethreading, or possibly buying a new cylinder head. Just curious I have never heard of this happening before

-Karl

A friend and I did the plug change last. When we did it actually that boot loosened up and the car started misfiring. So we checked all the boots and really tightened them down with a large vice clamp wrench(don't know my tools). I changed the plugs out about a year ago, I didn't have any problems with the car till now.