I need help findinding out what i got?

i had a good friend donate 2 brake set up's to me they look like 70 pin style calipers he swore one was from a A body they look just like an E body brakes is there anywhere on the caliper/rotor/spindle ie part numbers that will tell me what i got? and can i use these on my 76 dart sport will these just bolt on the A arms? thanks i can post pics if needed