Thanks for the help and suggestions.

I ripped the old master cylinder off and went to a local auto parts store (not a chain place like NAPA, Advance etc) and the hot rod guys got me a master cylinder that would work.

Best part is that they had one sitting on the shelf from a 76 Chevy ton truck. Has huge (like 3x the reservoir) size of what I had and was already set up for disc/drum brakes. Its a tight fit mounted on the frame rail between the floor but it fits and doesn't hit anything.

No proportioning valves or residual valve. Bench bled the master, bolted on, bled the lines and drove it. Stops straight and the pedal feel is great - almost like a newer vehicle.

There is a new issue though. Sometimes the calipers seem to stick and not completely release. I lubed all the caliper slide pin bolts with the special grease or whatever it is that they come with and they move better but not quite right.

Any ideas for that?

Thanks again for the help and suggestions - I was out of ideas.

I may drive a VW, but I love my 52 Truck...