The Kelsey-Hayes Disk Brake Swap Thread

Okay new guy here trying to do the research I just boought a '64 Valiant convertible, pulling the front wheels I was pleasently surprised to find these 4 piston calipers with 11" rotors. They look just like what the swap shows.
I did see the Rock Auto parts list as well.
My question is are these OEM parts from a later model Chrysler product? If so, what years/models?
While my car has a slant 6 it also has a 4 speed trans with 6-14-77 stamped on it. I also found a solenoid trunk release with 1977 on it. Just trying to sort it all out.
TIA for any help.