Scotty - you've helped me on a few issues - this (hopefully) will be one of the last. 2003 Expedition 4.6l - Blown out spark plug #2 and had it retapped. Mechanic said the new plug went in and is holding but "it went in really easy" meaning he didn't know how long it would last as is. Is there a trick to hold that plug in tighter (Like a JB Weld type material)? - the truck runs GREAT - shifts smooth, no hesitation, etc. I just know at some point its going to blow that plug again and I probably won't get as lucky as I did this time. Just need an idea to seal that plug in there - 200,000 miles on the truck - just want it to last another solid 12-18 months of in town and 30 mile high way trips.

Yes, put JB weld on the threads and put it back in, that can last a lot longer.