Dana 60 under 73 swinger..need id
Looks like that car has a 3" spring relocation, which means that axle has probably been shortened.You can see the empty stock spring mount (top arrow) and what looks like it could be a weld inline with the bottom arrow. Right at where the tube swedges down?
I would be looking to get new axles and brakes as well, but be sure to confirm the length and spline count first. DoctorDiff should be a good resource for you!