The Mustang spindles have different angles built in, IIRC, but maybe an alignment would get you close. The 70 Mustang uses the same spindles as all drum brake Mavericks, 6 cylinders included.
i have stock 65 - 68 (or something like that) 4 piston disc brakes on my mav i got them with my 72 mav then put them on my 70 mav and yes i just bolted them on
1970 Mustang disc brake spindles are different that 1970 Mustang drum brake spindles. The 1970 Mustang drum brake spindles are the same as was used on Mavericks for several years.