Liberty Rear Disk Brakes for A-Body

If you don't care about a parking brake you can buy aftermarket disc brake brackets that weld on your axle tubes...maybe $12.00 each. You use GM metric calipers and whatever rotor you want. I used Mopar mini van pieces last time. Might have $75.00 in the whole deal.
Yep the weld on brackets are a great idea. I have also seen the GM metric calipers with an integral built in emergency brake cable crank on them. Very similar to 87-88 dodge Daytona Shelby and Daytona Pacifica rear calipers. This way you dont have the additional having to fadiddle around with shoe brakes for an emergency brake.