Looks to me like a Borgwarner diff.
The tag on the filler plug suggests LSD.
I would guess its out of a pre XE ford being drum brake and leaf spring.
Ive been thinking about putting in one of these out of a skyline because they are disc brake and the silhouette's are LSD, 28 spline and 3.89 ratio. The only thing is you would have to get it shortned, but I recon it would be un brakeable in a 1200.
The 4cyl nissan pintara's had the same diff but it was 25( I think) spline and 4.11 ratio
These are the same diff that the VN V8 commodores run
