Right going on your details in the top right its an 85 VK. So it should have a Borg Warner diff.
This pic here is a 6 cylinder 8 bolt Salisbury.

The difference is the cover plate, the Sals is more rounded edges, the B/W is more hexagon shape.
Also the B/W diffs are a lot stronger, better for parts. The Sals diff parts are very hard to come by these days.
Cheers Damien"SL/ENUT" Smith, The SL/E Fanatic!
A lucky owner of 2 SL/E Commodores, a rare VB SL/E and a 2 tone VC SL/E. Just need a VH SL/E and have the set!