Using mustang rotors for 4.5" bc

After being involved in a BO29 restoration learning a lot about these car. Chrysler actually made large bolt rotors on the a body spindles that they used on the 68 Hemi super stock cars. I aways thought they use B Body brakes, not true. Its to bad that Chrysler just did not just start using them on all A bodies. They were also available over the parts counter. Very hard to find, as I am looking for a pair of these rotors.