K, what I think it might be is:
Motor was running lean.
Vacuum leak on the motor faulted the timing.
Cracked plug couldn't cool.
Cracked plug burnt up.
Other cylinders stayed lean.
Cylinder 2 couldn't fire many, if any, times.
Extra fuel in cylinder makes plug show rich.
That's kind of what I gathered from what everyone says and put together as pretty logical.
I can't try another plug right now because the motor's out of the truck to be rebuilt, again, but I'll make sure that the new set of plugs don't get dropped. The old ones might've; it happens.
Thank you, guys!