Will try to post a few more photos. Took the engine out of the car and started taking it apart. Found several broken piston rings, so I am glad it did not start when I tried to crank it last week. Found a definite ridge in the top of the cylinders, so it will need to be rebored. Internally, this engine is very clean--virtually no sludge in the oil pan. It appears to have had a valve job in the past, but no lower engine rebuild, which is due now.
It also needs a new clutch and pressure plate. Does anyone have a good source for that? CARS, Inc. has clutches for other 1960s Buicks, but does not list this one with the 401 V-8. Still need a passenger side engine mount auxiliary plate. Buick Farm no longer stocks them.
Pete Phillips