@ScampMike saw your posts about plug changing. I did the Magnum with over 150K. Was a bit of a PITA, cause the intake plenum covers a few plugs. Definitely worth doing though, picked up a few mpg.
I plan to pull a couple of them this weekend and assess the yay vs. nay of it all... I'm sure it can't hurt, but the truck really is running fine (good God - did I just say that out loud!!? I SO know better..)