I was surprised to find one of my spark plug threads stripped in the head on my 1989 B230F. It holds the plug, but won't allow any torque. Although the head could use a rebuild (only 231,000 miles!), I'd rather hold that off for another day.

I used high-temp silicone sealer on the last plug put in and only lightly tightened it. I have this vision of a plug shooting out the right side of the engine bay while cruising down the highway!

I hear that there are inserts one can use to provide a temporary fix in this situation. Can anyone guide me through the technical aspects of this work and where I may get the correct parts? Also, do I need to change that plug to a different thread size?

I appreciate the help!