Help me ID this dana 44 axle please

[Critter]

I'm having some trouble figuring out what this axle came from. Its a d44 rear, 6 lug that is currently under a 66 GMC 1/2 ton 2wd. However from the terrible welds holding the spring perches to the tubes, I can tell it isn't original to the truck.

I have already replaced the cover gasket and all the brake components (shoes, springs, brake cylinders, etc). All of these components where ordered for a 66 GMC 1/2t 2wd and they were identical to what I pulled off. The difference became apparent when I went to put the new drums on. They aren't as wide overall. The actual shoe friction surface is the same width between the two (the shoes are 11"x2") but the original drums have an offset of about 0.75" that increases the distance from the shoes to the axle flange. The replacement drums I bought are flat across the front.

Like these pics...




This axle has a width of 61.5" from wheel mount surface to wheel mount surface. I cannot think of anything from GM that was this wide with a d44. The drum from napa lists a "height" of 3", the one that came off the truck is about 3.5". I've checked 67-70 dimensions and 4x4s and whatnot but no d44s have a drums like these. Where am I going wrong??? I'm sure its something obvious.