hey gatorfly; do a search for "disk brake conversions" and you'll get 1000 threads on how to do this. there are multiple ways to go: Kelsey Hayes, aftermarket kits, and so on.
However; the easiest and cheapest way to go is: Find a donor 73+ A body with disk brakes. ASSUMING a functioning brake system, take the UCAs, spindles complete with rotors, calipers, pads and hoses, proportioning valve and master cylinder. Those parts are a direct Mopar A body bolt on. (steel lines are needed too, to go from a single pot to dual master cylinder)
If any or all of those parts are worn or bad, the: Master Cylinder, Calipers, Pads, Rotors, hoses, seals, bearings, UCA busings, Ball joints are all available at your local parts store. Specialty shops have repop proportioning valves too.
The only donor parts that are needed off the car are: UCAs, spindles and caliper brackets. spindles and UCA sets go for ~$300 or so. If you pass up the UCAs, you can get tubular ones for around $300. Get RMS adjustable UCAs. (my opinion, they are the best).
Total brake upgrade? Figure ~ $300 - $700 using mopar single piston calipers from a stock 73+ A body.
NOW: you'll have large bolt pattern (5x4.5") up front. leave the back SBP or just throw a LBP rear under it. LBP S6 open rears are nearly free for the taking.....
