A Body 8.75 housing/axles dont match

The only way those axles came out of a Duster with an A body 8 3/4 is if they are aftermarket units. No A body 8 3/4 ever had large bolt axles. Now, if they are aftermarket axles, do they have the "Green" style bearing on them???. If they do and you are trying to assemble your rear end with a center section, you need to remove the thrust button in the center section. The thrust button is used to set the backlash on the OE tapered axle bearings but is not needed with the Green bearing setup. I just measured a standard small bolt axle from an A body rearend and it measures 25 7/8" from the back of the flange to the tip of the splines.

Also, your measurment of the perch location and flange length is critical in identifying the exact housing you have, so shoot us an exact measurment of the perches. A body rear end flange to flange is 51 5/8" and the perch center is 43". Good luck with your project, Geof