When I had time to start checking Mr. Chevy over after I got it home, I was looking at the way Van had put the car away.  The freeze plugs on the left side of the engine were taken out and the block left dry.  For long term storage this seemed to be a good idea.  When getting the car ready to go back into service I took the other freeze plugs out and blew the coolant passages out with 180 psi compressed air.  There was a fair amount of rust and dust that was cleaned out.

At the sale I pulled the dipstick from the crankcase and the oil appeared to be virtually brand new.  It looked like Van had drained the old oil and put new oil in for long time storage.  When I primed the oil passages I noticed the rear main was leaking which was proven also the first time it ran.  My guess is after 30 years the rear main seal had gotten pretty hard.  I picked up a new rear main seal and new pan gasket to do the repair.  I drained the 8 quarts of oil and dropped the pan.  I had a big surprise when I looked into the oil pan.  There was a heavy black layer of sludge on the bottom that I had never would have suspected to be there.  My belief that Van had changed oil before walking away from the car was wrong.  It was clear that what had happened is that after 30 years of setting still the contaminants had settled to the bottom of the pan, completely!  In this respect I was glad the rear main had leaked so I was able to wash the pan and change oil again.  Hopefully, now the engine is as clean as new.