This is a simple and inexpensive way to convert a Chev 10/12 bolt rear to disc. I did this on my 41 and have over 50,000 mi on the conversion so far. The first step is to get a pair of rear caliper brackets from an 80-85 Cad Seville or Buick Rivera. While you're getting the brackets you should also get the calipers as the core charge on these is quite high. You will not pay as much for the junkyard ones as the core charge the parts store hits you with. At least that's the way it was when I did mine. Next go to the parts store and buy a pair of rotors, plus calipers and pads for an 80-85 Seville. The bolt pattern for the rotors is 5 on 4 3/4 so no redrilling of the bolt pattern. Now that you have the needed parts remove all the drum brake parts from the rear-end. Check the hub center of the axle to see if the rotor will fit over it. Mine wouldn't so I had to turn/grind it down a bit to fit. Now to see if the assembly will interfer with anything on the car. On mine I had to reclock the bracket position to clear the sway bar. No problem just weld up the factory holes and redrill for the position you're installing them in. Look at the pics I put here as you need to put a spacer (1/4") in to get the caliper in the right position with the rotor. When you weld this spacer on also tap it because the caliper bolt is just barely long enough to reach the original threads. The one pictured is an uncompleted one. You may have noticed when removing the parts from the junker that the caliper is hard lined not a rubber line. I didn't trust this type of set-up and used the traditional style flex line. The one I used is Wagner #11190. One last thing if you do not want an E-brake just use the front calipers. The front and rears will interchange