Don't know about the 12" brakes but you can go to a salvage yard and get the vacuum booster, master cylinder, and you'll also need the brake pedal from any G-body car besides a TR...non-turbo Regal, Monte Carlo, El Camino, Cutlass, Grand Prix, etc. I really wish I knew what kind of booster was in my car so I could tell people because it looks so much better than some of the G-body boosters I've seen but it was put in before I bought the car. You'll also need one of the billet vacuum blocks with the extra port on the driver's side for the vacuum brake booster.