Witch Master cylinder? HELP!

I converted my 64 Val to dual circuit and used a 15/16 bore MC run manually. (no need to get crazy here with anything special)
I originally used the 64 push rod and everything seemed to be fine. But then I noticed that the rear drums were getting very hot, even when just cruising and not using the brakes very much. Also there was a lot of rear brake dust being generated. Figured out they were dragging and replaced the push rod with an adjustable (longer) as the front piston in the MC was not retracting enough. (The front is actually for the rear brakes)

I ditched the factory proportioning stuff and just used a Wilwood adjustable in the rear circuit. The front outlet is plumbed directly into a Tee and then to each front brake. But if you like it fixed, thats your option.