I got 40K on my plugs, was told they could get carbon'd up & strip on the way out...Is there special/different plugs I should replace with? -or- stick w/ O.E.M.?
Thanks...

Stay with oem. And yes, they can strip the threads on removal. I've done many of those. They make a lot to install inserts of that happens.

I would use anti-seize and a torque wrench on the new plugs. If you have exposed threads extending into the combustion chamber, I have ground extra threads off then use a thread chaser to true the threads before installation. The inherent Ford engineering problem is, while you have a very long thread portion of the plug body, only the first few threads actually engage in the head, then there is a void, then there is the tapered seat for the plug. I believe Ford corrected this in later model heads. There are stories of "ejecting" plugs out of running engines when the threads failed.