Drum/drum to disc/disc proportioning valve

you should get a new adjustable valve andplumb it in right from the start you'll wish you did. also get a newer master cylinder fo disc / disc. It combines the resevoirs to commondate the exttra fluid in the rear brakes as they wear. a drum/drum both are small and a drum disc the front resevoir is mall for the rear brake's. I got a master cylinder for a newer car with a plastic resevoir and when you fill one side it fills both. and it will have the proper proportioned piston size for disc / disc. You can see in the picture a newer master cylinder from a dodge truck. note the adapter we made to convert from 4 bolt to 2 bolt. The other picture below is with the original.