My ‘57 3200 appears to have the same casing.
I captured these details a year ago.

10 Bolt
17.5 turns x 2 = 35.0 or 8.25
AF1126

Photo attached.
Attachments
0E0863EF-D282-417D-812A-CAC1336700F5.jpeg (338.09 KB, 143 downloads)
‘57 3200 Differential


1957 Chevy 3200
Daily Driver
PS, A/C, Tilt column, Rebuilt 350, Rebuilt TH350, Reupholstered Bench Seat, sound proof/insulated, LED headlights/taillights/backup lights/interior courtesy lights.
Follow in the DITY