Posted a response on another forum and though I would post the same info over here to help members currently and in the future.
Here are some pictures of a 69 Dearborn installation that might help
Short cable from under dash attaches to the long main e brake cable. Short cable is attached to the bracket welded between the frame rail and cross member. On the other side a arm (shaped like a flattened "C" holds and routes the long cable towards the rear on the other side. Attached to a bracket welded to the floor.
Long cable attached to the rear frame rails at the rear under the rear seat riser
Cable ends attach to the rear brake backing plates and to the activating arm on each side
Hope they help