F-body brake calipers?

dano said
Shows 75-down are 2.6" and 76-up are 2.747". The mounting clips look to be the same from 73-89.

ok so what I was lookingathttps://www.ebay.com/itm/304065130934 listed for an 82-89, so I'm guessing there different.

Also could anyone tell what the 2 rubber bands are for?