So I was at 172,000 plus miles and thought I would replace plugs, wires, valve cover gaskets. I did not feel a plug/wire breaking down just thought of it more as prevented maintenance. The plugs looks a lot better than I thought they would.
So 2, 3, and 8 was really carbon fouled. 4, 7, and 6 seemed a little hot. Really 2, 3, and 8 is about what I expected them all to be. There is a lot of highway driving, is the DoD/AFM the reason for the big swing or do I have some sloppy valve guides?

Thoughts?