If it has the right width on the spring pads, then it is probably out of a 67-70 Mustang/Cougar. You can use those, but you need more backspace on the rims than you would normally use.
if your talking about the spring perch's my dad said we can just cut those off and move and reweld them like he did with his mustang.But how much off set would you say?
I used a 70 Mustang rear on my Comet and it fit perfect with 03 Mustang Mach I style wheels. They have a lot of offset and usually require spacers on the stock rear ends. If I remember correctly the mustang rear was about 3" wider overall. Phil