I am in the middle of replacing my front drums to disc. The master cylinder is a 1967 dual reservoir with both chambers of equal in size. I am not sure if the front chamber port is for the front brakes. The donor proportioning valve and plumbing fits that way, but I have seen some cars the other way around. I would like to know which chamber port has a residual check valve or if either of them do. I want to get this right the first time.

Thanks