It's an 8.8 out of a Ford explorer. Alot of them were LSD and all explorers have a 31 spline axle and 95 up are disc brake. Pretty common swap in the states for alot of hot rodders. Explorers went to IRS in 02 with the exception of a few sub models.
2-7/8" of the drivers side tube is cut out, making the drivers side an equal length to the passenger side. Then a passenger side axle is used in the drivers side. It's almost identical width of an A body, hub to hub when completed.. Just a fuzz narrower. So, I built a solid lsd, with disc brakes (5 x 4-1/2 studs) for under $200 with new seals, perches etc. Swapping gears to 3.23 so add a few hundred more. As opposed to near $1500 for an A body.. Even building a b body will run ya a grand to build with the same specs.
