"C" body caliper mount brackets DO NOT fit an "E" body spindle.
They are to big, and the bolt hole spacing is way to wide apart.
Doesn't work.
You need mounts from Cordobas, St, Regis, Newports, of the later 70's to bolt up.
Same thing with rotors, to be needed from those cars.
They are 1.000 inch thick, and "C" body rotors are 1.250 thick.
C's are to wide for E body spindles.