On the 73 up brakes, if you source M body calipers off a diplomat or fifth ave from 84-89. They use a larger 2.75" piston compared to the 73-76 dart 2.60" piston caliper. This caliper will work with the 73-76 dart brake pads as they are the same. If you can find caliper mounting brackets from 75-79 cordoba these will allow you to run an almost 12" diameter cordoba brake rotor on your A body spindles, along with the larger diplomat calipers this will help improve the braking at the front along with the hydroboost setup.
