The Stovebolt Site Forums The Shop Area Engine Shop Is the motor frozen, or just stuck? "it ran when I parked it there"

At first I thought that pretty much says the front two cylinders were full of water at some time and pumping water up into the valve train.
Second thought, why no rust or milk in rear valve train?

Evidence shows the truck was not run after water incursion..soooooo...

Wild A$$ Guess: Water got in to valve cover and sat there a long time. Truck was parked "down hill". Still don't think cracked block.
Possible condensation inside valve cover and truck sat "down hill" because front sank down in the mud.....or rear end was up on blocks.... or front tires were flat causing tilt....for 12 years.

Anyway, I guess now you know what cylinders are stuck and what cylinders those rusty plugs came from.