[JM 35 Sedan]

The direction of movement would depend on various factors. The banjo rear could be nailed in place such that it won't or can't always move back. One scenario would be rear radius rods attached to the frame instead of the torque tube. I agree that the thickness of that flange is not that significant and that thickness increase can be moved forward by shifting transmission and engine forward slightly at there mounts to the frame. I'll read that old thread to see exactly how the rear, transmission and engine were mounted to the frame.