Heads up to those that install a 2 bolt aluminum master cylinder.

Disk always has a larger reservoir as the caliper pistons displace more fluid that the drum brakes.
I don't know why the MC has anything to do with proportioning. Usually the prop valve directly applies pressure to one side and has a tight spring that moves with pressure to delay uncovering the other port? Not sure what gets the first application. What you wanna lock up first?