I had a glow plug stripped out in my 6.2 once.
What the mechanic did was put in a thread insert, and then he used a compound that he used to put in valve inserts in, and put anti-seize on the plug threads. He told me not to remove the glow plug until the engine had been driven for awhile, since the heat is what would cure the compound that he used.
So, in this case, I would think that using JB weld on the thread insert would work just fine. I would use the 24 hour cure though, since I think that stands up to higher temperature.
You may want to check that though, what the heat range is.
Another thing, get yourself a set of reverse drill bits. Many times, when I had to do this, the act of drilling with the reverse set would remove the bolt 90% of the time.
I would recommend using the valve insert compound, but I don't know what the name of that is. Just know that it could easily withstand the temperature range of the head.
2016 Colorado LT, Laser Blue,CC,4WD,2.8L diesel, ARE Topper
Last edited by Marty G; 02-21-2017 at 09:15 AM.
Reason: add information