Jerry,
You have stated the truck wouldn't restart after the disaster, but it tried. It did start later after sitting for some time.
When it wouldn't start the first time, what was it doing! With the oil pressure question comes the thought that some bearing or clearance might have partially seized.
A quick look at the oil for dilution and fuel smell would be a starter. Although your rig might have a mechanical gauge, I would still tap into the system with a known good pressure gauge just for a pre-surgery benchmark.
As noted above, pulling the pan will allow you to inspect the suction side of the pump, and the discharge pipe that leads into the engine.
Hopefully the pan is a easy drop on the '57 pickup. Scratch your head for a plausible explanation before you rip into it. Contrary to popular belief, "sh&t doesn't usually just happen".
Stuart
