Prop valve or not?

[Bamamav]

Gathering up the parts for the Lincoln brakes. Got the dual booster and Corvette style master from Speedway. Will I need an adjustable prop valve for drum/ drum brakes? The original setup had a single line master that went to a T. Mine is a dual line, and will be firewall mounted. Oh, rear brakes are 10" Fairlane, front are 10" or 12" stock 47 Lincoln, haven't pulled the front drum off yet to measure them.

Another quick question, anybody know if the Lincoln and Ford wheel cylinders are the same?

 

[Torchie]

Although some of the new dual MC kits that are for sale say that you need a proportioning valve for drum to drum as I remember it they were not used on older cars with dual MC's back in the day. The system works the same as a sinlge line MC but the use of the dual MC adds a safety feature.
I thought the the purpose of the valve was to allow for the use of Disks on the front and drums on the rear and to make up for the different pressure needed to make them work together.
So I would say that you don't need one.
So lets see what others say.
Torchie.

 

[Bamamav]

That's what I'm thinking, too.

 

[21willys]

I always thought it was to keep the rear brakes a little "weaker" then the fronts so the fronts would lock up first.

 

[jmlcolorado]

I running one in mine even if I might not need it. I'd prefer to have the adjustability if needed, plus, I'd rather do the little extra work now rather then after I get the truck on the road to find I really DID need one and don't have it.