Hi i am new to this forum, i have a question, i have a 2001 Ford F-150 5.4 Litre 4 WHD in the pasttwo weeks i have had #2 and #3 spark plugs blow through the head as you probably aware this is becoming costly anyone outthere have an idea how i can prevent more of this

 

I believe there has been an issue with spark plugs stripping out on those heads. There is a fix for it, but I hear it is costly. I'm sure others on here can give you more details. Doing a search may yeild more info, too.