Ok guys, wanted to follow up in case anyone else ever needs this part. I found the part listed in a couple of places on the net. It was previously part # GM 5575614 and it was called a "oil filter by-pass valve".
It was superseded by a newer part, GM Parts 25013759 Oil Filter Bypass Valve.
This part can be found from Summit and Amazon.com, among others.
The original part number is even called out in the old book "How to Hotrod Big-Block Chevys" on page 121: "Either plug the hole as the professional racing engine builders do, or follow Chevrolet's published "safe" recommendation and install a six-cylinder oil-filter by-pass valve 5575416.".
The part cost me less than $8 dollars with 2 day shipping from Amazon.
Dan
