264 GL 1977 3.54:1 Diff type- 1030 or 1031?

[volvo264]

HI Folks

I've been researching options to upgrade this open diff with LSD

Trying to figure out if its 1030 or 1031 Diff ?

Can you tell visually what diff type ? I think its a 1031 based on the diff fluid capacity i replaced?

Diff Plate have the following stamp.

FABR NR = 14113
Volvo PART NR = 255762
RATIO = 3.54

In TP30039/2 it says 1031 used 3.54 ratio and 1.6 L of final fluid. I definitely used ~1.6 liter when replaced last and does say the same in owners manual.

Found some reference under this url talks about Volvo 260/PRV with LSD on 1031 type diff.

http://people.physics.anu.edu.au/~amh110/Diff_LSD/diff_lsd_volvo_dana.htm.

Attach some pic of the diff and bits.

Much Appreciated.