After 70k miles, and constant engine fiddling and spark plug reading, the sparkplug thread on the right head of my Lemans IV was worn out and partially disintegrated. While I had the heads off, I had the cylinder head shop install a Helicoil in the head. That lasted all of 2000 miles until, one day, the Helicoil pulled out, uncoiling as I removed the sparkplug. This time, I used a Timesert insert. So far, so good. www.timesert.com
Ed Milich
