Update:
OK, now I've started doing something I didn't want to do with this truck -- throwing parts at it.
I have a buddy, he used to live around the corner, he's a Ford factory trained tech. Good guy, I don't really want to bug him, but I ran it by him.
He said "when it's stalling, are you losing fuel or spark?" Put an inline spark tester on and cranked it, sure enough, had spark. I then key on/key offed it to try and build fuel pressure, and it barely leaked out when I pushed the pin on the Schrader valve. So, no fuel, apparently. He told me to test the 2 wires at the inertia switch, neither had power, so he suggested the fuel pump relay, which I replaced. Still starts right up, may even run a little longer when I hold the pedal down, but when it eventually stalls, it won't restart, until I give it 10-15 minutes.
I guess it could be the fuel pump, but why does it start and rev at 2000 rpm for a couple of minutes, and when I let it try to idle, it dies and doesn't restart? And then restart after a couple minutes of wait time?
Doesn't make sense. Anybody got any ideas? REALLY hate to pull the fuel pump(s) before knowing that's what's wrong.
I'm going to head to Autozone to rent a fuel pressure gauge and see if I can figure out what's happening with fuel pressure.
Thanks
Tom