Relocating the rear differential 1.25” towards the rear of the vehicle on a 72 Dart

I'm just askin this but how can it ever make contact? Even at full jounce the tire will not touch. How can it move? It won't.
Yep … tire moves rearward as springs compress.

I did add a 1” aluminum block as a spacer to my Swinger so I could run a tire that would rub otherwise .