They are held in with C clips just like Eatons or aftermarket Auburns. The only thing different is the differential itself per the illustrated parts book.
I looked up the date of the sale of Auburn Gear from Borg-Warner and I was confused. It was in 1982, so 1983-85 Borg Warners could technically be called "Auburns", but the GM literature didn't change because they still called them "Borg-Warner" as late as 1990 in the manual updates. The Cone style clutch is a Borg-Warner design/patent going way back to the mid 60's and Borg-Warner sold tons of them to MOPAR for 8 3/4's.
I don't know what a 10 bolt WD is. The Spring retainer plates in the OP picture have the same semicircular cutouts, one side case window and 2 piece case as the ones in the GM illustrated parts book, so it looks pretty Borg-Warnery.