[Steve Shauger]

The pressure regulator (located on the drivers side subframe under door area) usage was primarily used on all disc brake cars, although for some reason some drum brake cars as well. The use is kind of a mystery because it was not used in the beginning of 69 and reintroduce in mid 69.

To some it up, given your car is a copo that was built in mid to later production, your car would have one. However nothing special about your brake system or the mounting of the regulator.