Identifying differential in allegro bay

[heavymetal]

I want to inspect the rear brakes and bearings on the 1992 allegro bay we just purchased. I think it is a dana 80 but I'm not sure. I pulled out the floating axle to see what tool I need to purchase to remove the bearing nut. The pictures of the bearing removal socket online show 4 sguare tangs 90 degrees apart but the nut on the differential I have has 6 round holes in it so, it won't work.
What do I have and what am I missing.
The dana web site shows identifing numbers on the right axle tube and I can't see anything on this one but the housing shape looks like a dana.
Also, this is a chevy chassis with a 454

Ed