That new engine, according to the numbers on it, is a 1984 305 out of a Caprice. It hadn't been in use for some time, and the freeze plugs looked bad, especially the screw in replacement ones. Good idea to change them, some were in bad shape, and someone had just left the old ones in the waterjacket, so there were a lot of plugs coming out of that block!
The waterjacket was flushed with the garden hose, and a LOT of rust and old engine parts came out
The flywheel and clutch assembly were mounted to the crank, as was a pilot bearing.
The 305 was just cleaned out and flushed. No special cleaning or such on the outside. As the starter was still attached to the block, a compression test was made, and its results was very good, all cylinders had between 160 and 180 psi, which is remarkably even for an old engine that hasn't been run in years.
Also all pushrods were rotating as the engine was cranked, which is a good sign, telling us that the camshaft and lifters are in good condition.