I Just did the plugs on my 97 GC last weekend (scars are mostly gone from the exhaust rubbing on my arm). 5 had probably been changed and had 70-80,000miles on them and were suprisingly worn, but burning well. #1 had never been done and had no anode left at the ceramic level. That one was very brittle and actually snapped off and scared the crap out of me, but got it out finally.
Here's my question all the plugs were actually burning pretty well considering how worn they were, but in comparing them to each other the #3 and #4 were definately burning a little hotter. Is this normal? Is this due to being in the middle of the motor? Only one had minimal fuel deposits on it and is it normal for only one to show something like that?

 

Pretty much normal.I replaced the plugs in my wife's 92 Caravan because she said it had started missing.When i took the first plug out it had completly worn off the center electrode and the ground (side) was worn off to a point.The others were about the same.
I did decide it was easier to change the plugs by removing the upper intake and going in from the top though.