So...update...I'm an idiot. The reason that one pin was dead is because I had disconnected the other end that goes to the coil when I tested it. That's why I couldn't duplicate it. However...
I decided to test the actual ignition coil while I was at it. You're supposed to check the resistance in 3 places. Well, the resistance between the outer most pins (B and C) is essentially supposed to be about zero (technically the manuals say 0.1). On my just pulled out of the box AC Delco ignition coil, it's a flat 0.5 no matter what. But on the Autozone one that's in the truck, it meters all over the place - 0.9. 10, 1, 25, 1.5, 50... So I'm gonna try and change that coil out...