Your 62 & 64 had single reservoir master cylinders, what you need is the later distribution block for a dual reservoir drum brake system. There was a discussion about the early drum brake versus disc brake blocks here about a week ago that showed pictures.
I dug threw enough box of parts that I found some dual dist. blocks. What models who knows but I needed block to correspond to the pre bent lines so I just ordered their block I hate flanging brake line with my sorry flanging tool.
I bet all disc brake systems also use a proportioning valve.
