Welcome to the forums, we are pretty good at helping folks here but to the best of my knowledge we don’t have any clairvoyants on board.
Could you perhaps supply a little bit more information as to what your query is?
I think it’s just a “Wow! I can’t believe how crappy the old plugs were!” type post.
That’s how I read it, anyway.
No being present to make a definite diagnosis, I’d say all the muck on the porcelain
is from blowby from the leaking seals around the spark plug wells. The cam covers are
notorious for failure around the top of the spark plug wells. If you’ll examine the mating
surfaces where the seals ride you’ll likely see breakdown of the shoulders that support the seals.
Sorry to be the bearer of bad news but that’s one of the few weak points of the AJ16 engines.
Thank you everyone for your thoughts. It was the first plug change I’ve done on it since I bought it 4 years ago (its been garaged for 3) and I was sharing how worn the old plugs are.
It was running fine I’m just catching up on regular maintenance.
Next weekend I’ll do a diff drain and grease the ujoints.
I have a road trip coming up. I’ll check the new plugs after that and see if they are discoloring.
The old plugs were made in France. Any idea if champion still manufactures there? Might give me a clue as to how old they are if production was moved out of there years ago.
Just make sure you can open the fill plug BEFORE you drain the diff. Just sayin 
Will do 
!
I watched XJ Jesse’s video on YouTube on draining the diff and that is the first thing he says.