just to update, I went ahead and changed out all eight plugs and all eight cops over the weekend. all is well Expedition is running excellent, gas mileage has substantially gone up.
also I have to say this job isn't as painful as every post I've read makes it sound. They make it sound as if that number 4 plug (the back one on the right side) specifically is nearly impossible to get out. Although it was no picnic at the beach, I found it pretty easy with a 4 inch extension, a universal and a 10in extension. so for those people out there who have been avoiding doing this job for the fact that everything they read makes a sound so hard, I suggest just get in there and do it.
I had been putting this job off for over a year due to worries and concerns that I have read all over every page on the internet. And all I did was cause more damage to my plugs, and inevitably my engine.
thanks again to everybody that offered up some info for me. I just really like to understand what's going on before I jump into stuff.
Dont cross your fingers just yet, many times we see this here when people change plugs and coils and report exciting news then a week later the gremlin strikes again