Up on offer today is a water pump core.  Casting 3931065 for 1969 model year 396 & 427, date coded H 15 8 (August 15, 1968).   About mid year they switched to casting 3969811.

This is the tall water pump, as in 1969 the alternator moved from the drivers side to passenger side of the engine.   The bolt hole for the power steering pump bolt doesn't seem to be tapped.  I had one like that a few years ago, I just tapped it and installed the bolt.

$100 + postage.