Got my truck back from the mechanic, they did replace my sparks. I asked for one, as a learning tool. Here's what it looks like:
The outside electrode is a pretty even gray, with just the slightest bit of yellow speckling on one side. The tip looks a tad narrower than the rest.
The center electrode is grey, the top isn't flat- it's markedly angled down toward the outside electrode.
The insulator is pretty much white/very very light brown speckled. Along the top edge it's a yellowy brown.
There's barely any corrosion at all, anywhere, but both electrodes, to my eyes, look worn.
The threads look a bit dark to my eyes as well.
According to the web page that was posted here a while back, and another one I googled up, my engine's running a bit warm. One site suggested something about vaccum leaks (it was a bike site) - and indeed my truck still throws a P0455 "Evaporative Emission System Leak Detected". Could these two issues be related?
Truck runs fine, but still seems to lack a bit of the the g-force acceleration it used to have.
Thanks for any responses. (and TGIF!)
jmc