Upgrading my Master Cylinder & Prop Valve - Thoughts On This Combo?

Drums do not have a prop valve. The difference in the master is that drum masters have what is called a "residual pressure valve" which the disk section of the disk master does not have. On my 67, I didn't even change the original 67 9" drum master. I simply ran a nail through the residual valve(s) (I have 4 wheel disks) and used the old master