[DanEC]

One thing ERA does is mount the jag differential in a cage that has two mounting bolts at the top to the frame and allow the cage to pivot or swing fore and aft slightly. That allows the cage to "adjust itself" slightly as the axles and radius rods/traction rods cycle up and down with the lower control arms. Their radius rods are also threaded which allow a small bit of adjustment of the wheel placement in the wheel wells and of the differential yoke angle (side benefits).