Well, I went and took a look at it. Body seems solid. Trying to identify what engine it has in it. I snapped a couple of pics but I can't seem to find info on the numbers. I must be reading them wrong.
This is right next to the spark plugs. Looks like it says 4883F20 or maybe 1883F20. Neither of these numbers yielded anything on various sites I've checked.
And here is another stamp on the exhaust manifold (I think?). 3820578, or maybe 3829578. Hard to say. The 382 part seems pretty clear but even that yielded nothing.
Any ideas? Tonight after my daughter goes to sleep I'll post more of an update on the truck, along w/ a few more pics.
Cheers