Dr. Diff 1/2" offset hangers on early A-body?

I put them on my 64. I think the difference is the spring bushing bolt hole. I used springs with the larger front bolt hole so they worked well. If you are keeping the original size front spring bushing hole the special supplied bolt will be too large. If you have the larger bushing all will be good.
did it make a difference in tire clearance? I looked under there years ago and decided it was minimal gains.