Disc brakes for 8 3/4 using only Mopar parts

74-75 Chrysler imperial had rear disc with a drum E brake in the rotor hat.
Probably uses obsolete rotors today?
Yes, I did on my Dart. Literally a bolt in with all MOPAR parts and E-brake. The Calipers are the same as the 73 and later A-Body and are readily available.