Disc Brake Spindle Question

I know this is a B body question, but here goes. I have been given a set of front disc brakes off of a 1970 'Cuda. I want to convert my 1967 Satellite from drum to disc.

The 70 'Cuda front discs use the two-piece rotor design and I want to use the later ('73 and up) unicast rotor. Does anyone know for sure whether or not I can use the later unicast rotors on these spindles. Or am I stuck using the hub/rotor setup?