UPDATE:
In addition to the new points(.020), cap, rotor, and plugs(.045), I replaced both fuel filters (fuel lines are only a couple years old), and checked for vacuum leaks (none).
I adjusted the valves. I also did as Volfandt suggested and held a piece of paper over the exhaust pipe for about 30 seconds as it idled. Not only was there no sign of a tight or sticking valve, but the paper came away totally clean except for sprinkles of water.
I even replaced the carb with a known good rebuilt one. It ran the same, so I addressed the timing.
Timing and dwell were off so I adjusted dwell to 35-36 (needle steady as a rock) and timing on the BB at 550 rpm. I guess I'm confused as to how you're supposed to set the dwell at 30-38 and yet keep the points gap at .018
Anyway, the truck ran like a champ the rest of the day. But the following morning, even though it started up and purred, I could hardly give it gas without killing it. This morning (33° outside) she started right up and is running great.
If you have any ideas, I'm listening, but I think this is something I'll have to figure out myself.
