Here we go again (sigh) - having to reply to and explain my own posting. OP stated his calipers came (he believes) from mid 70's A-body - - so they would not have pins. Thank-you. :p
Whatever bud. The car is 50 years old and assuming it has to have sliders because it’s an A body and ordering parts could easily get the OP the wrong stuff. The OP isn’t sure, and it could absolutely have pin type calipers on it. It doesn’t matter at all what it should have.