The 340 is out....again.....
UPDATE:
Received a call from the shop yesterday and the real issue has been identified as a missing freeze plug. Apparently this had been removed by the first engine shop I had hired to do the rebuild and was never replaced. It's not one which comes in a rebuild kit of plugs, and shouldn't have been removed in the first place from what I'm told. The plug is visible in the closeup photo, dead center and aluminum colored.
UPDATE:
Received a call from the shop yesterday and the real issue has been identified as a missing freeze plug. Apparently this had been removed by the first engine shop I had hired to do the rebuild and was never replaced. It's not one which comes in a rebuild kit of plugs, and shouldn't have been removed in the first place from what I'm told. The plug is visible in the closeup photo, dead center and aluminum colored.