Went to pick n pull and got some extra gauges and started experimenting. I cut the edges out so light shines through. Didn't come out like I thought. So I just put it back the way it was. Also tried to sand the blue off so I can have white numbers but it doesn't come off.
Cleaned throttle body and IAC motor/valve and started installing new Champion Copper plugs. I haven't gotten to the difficult ones yet, but I believe these are the original spark plugs and I'm almost at 100k miles now. For being original, they tell me the engine is running great. However, they did need to be changed. The center metal conductor things were a little corroded down to where they didn't stick up out of the porcelain insulator very much, so the gap was almost twice what it should be. But the plugs in general looked to be in great shape. No rust, and mostly white (slightly browned) insulators, etc.
I'm still finishing up the project, but considering my 4.7 Power Tech has ran great and idles fairly smooth, with only slight "sputter/hiccup/glitchiness" if you pay close attention, I don't know if I'll see much improvement. If anything it should just run flawless and idle completely perfect. And as good as the plugs looked for never being changed, they had the equivalent of a super big gap on them, so I don't know what improvement I'll see after changing them. But I expect the fairly carbon deposited IAC and throttle body which are now nice and clean, should make the idle perfect. It already ran smooth but maybe I will get a slight MPG boost or slight boost in power with the new plugs? Doubtful, but it's possible.
I need to post picture of the other stuff I've done lately, which include a D-ring shackle mounted in my factory hitch, a new Pioneer head unit, and some Plasti-dip fun!
EDIT: BY THE WAY, following the instructions on WJJEEPS.COM, the spark plugs take 20 ft. lb.'s of torque OR you can just tighten it an extra quarter turn after it's snug. When I get the plugs seated hand-tight, it takes a half turn to reach 20 ft. lb.'s and it feels tighter than I normally thought spark plugs should be. Does this sound right, or is my Pittsburg torque wrench way off? It doesn't seem excessively tight, but it's definitely passed "a quarter turn passed snug" (I think, since it's at least a half turn passed hand-snugged) and it's a bit tighter than I've ever installed plugs into a car when I've done it by "feel" in the passed (knowing you need to be careful not to over-tighten plugs).