Bob: I am always up for a part number challenge. We'll see how Bob P does in his quest, and if it doesn't work out, then we'll go the measurement route.
For some reason though, I think we went this route on the forum a couple years ago. Was it for this bearing?
The GM part number shows on this list of cross reference as well, which has a hundred numbers for that bearing:
https://mibearings.com/index.php?mai...ucts_id=281388
And of course, keeping an eye on ebay, or searching google for the Chevy part number should also get you there.