What disc brakes are these?

FYI
Those pictured are 65-72 small bolt pattern, two piece rotors.
Rotors & hub assemblies.
Two piece, 70-72 B & E body rotors are too big, and DO NOT fit, work, on A Body 65-72 spindles.
Wheel studs are what hold the two pieces together, rotor & hub.
Ahh ok, understood. Is it possible to keep these calipers and switch to the 4.5 bolt pattern? Rear is already an 8.75 with the larger bolt pattern and would like to have the front match for getting wheels...