Katfish,
I was kinda down this road before. I believe Chryco is talking about the 4 bolts that hold the 70-72 calipers together. The bolts run right thru the brake pads. I happen to have to 1 piece calipers on my 70 Challenger. Donated from some mid-70 A-body. The pads just kind of sit in there, nothing holding them in place. Hope this helps.
Mike