1970 Duster base model slant 6 rear differential 2070051 spider kit

Members give 7-1/4 axles away fairly regularly here, but if it's a 4-1/2 bolt pattern from a '70 duster it had been changed at some point in time to a '73 up axle. The ones that ran in later models (I am wanting to say late70s or early eighties, I can't remember the exact year that ChryCo standardized the U bolts and backing plates) with 10 bolt covers had larger 3" tubes that had the inboard six or so inches swaged down to the 2-1/2 inch axle tube bore size in the center section. From what I have been able to uncover here on the interweb, AAM started making the 10 bolt cover axle to use either Dana 30 or 35 components. I'm pretty sure this is when they became a C-Clip axle as well.
On a side note, if worse comes to worse, '84-97 Jeep Cherokees ran Dana 35s. They have a width of of 43-3/4 pad to pad and a total width of 60-3/4 drum to drum, and a 2-5/8 tube diameter. They also have a 5 on 4-1/2 lug pattern. So far, this is the closest thing I have been able to find for a modern upgrade for a 7-1/4 AAM axle that could possibly use the stock spring backing plate/shock mounts with only slightly larger U bolts and ovaling the holes fore and aft. But it is not much stronger than a 7-1/4 and is only a good option if you can get it for no more than scrap price. If it could retrofit a 38-1/2 inch wide spring pad center to center distance, an S10 7-1/2 axle could be used, 2wd 54.5", 4wd 59" outside width.