I purchased and installed the Right Stuff 4 wheel disk brake kit on my 71 Dart, but changed it up bit as I did not use the supplied brake proportioning valve. I used one of their OEM disc brake proportioning valves, minus the small add-on block. You may have trouble with the e-brake cables as the ones I got with the kit where even length. I had to purchase a separate long e-brake cable. The kit came with the small offset power brake booster and has worked very well, the car pulls down very quickly on emergency stops.
I did have some trouble getting the brake lines to seal properly to the calipers and the master cylinder has the typical leaking around the cap problem, I'm looking to replace it with a unit with screw on caps. Price was good if I remember correctly it was around $1200 bucks everything.
