I am new to the forum and realize now that this subject has been discussed
before.Yet for those interested,my engine had been making a slight tapping
noise for sometime.The night it blew out,the noise had increased about 15 minutes earlier.The shop I use (not Ford house) was able to bore out the hole
and install a insert.Not a helicoil.They checked the rest of the plugs and it cost
me $320.00 bucks.A lot cheaper than replaceing a head.Loctite makes a liquid
that has a breakaway torque of 25-80 LBS.Its called Loctite 222,is purple in color and has a 24 hour cure cycle.Next time I replace my plugs I belive I will
try one drop on each plug. Just FYI.