This morning I confirmed that the old E-1 engine in my truck does turn freely, which is a good start toward the possibility that it will run. When I bought this truck, it had been sitting for many years, with the prior owner having started a restoration (which is why the truck is so cosmetically nice) in the late 1990s. In fact it may have been 20 years since it last ran under its own power. Fortunately the E-1 engines in these trucks are notoriously bulletproof, and stories of these engines starting right up after sitting for long periods of time are not uncommon.
I used the hand crank that that every 320 came from the factory with to turn the crank pulley. Before inserting the hand crank through the front bumper I pulled the spark plugs.
And sprayed a liberal amount of WD-40 into each cylinder to lubricate them.
Here’s a short video of the E-1 turning for the first time since I’ve owned it and probably for the first time in many years (please excuse the Napoleon Dynamite-inspired music).