spring relocation inboard help

My 72 swinger with 265/50/15 rubbed before my front sway bar. I have a 3/4 offset mount and shackle kit too.

Enough squat or body lean, and my tires still rub just slightly.Where do they rub im looking at running the same size only 4.5 backspace

Rear rims are 15x8 with 4.25 backspace on an a body 8.25" with drums (56.75 wms to wms).
My 72 swinger with 265/50/15 rubbed before my front sway bar. I have a 3/4 offset mount and shackle kit too.

Enough squat or body lean, and my tires still rub just slightly.

Rear rims are 15x8 with 4.25 backspace on an a body 8.25" with drums (56.75 wms to wms).
Where do they rub I'm looking to run that size only 4.5 backspace