KELSEY HAYES PROPORTIONING VALVE KIT SOURCE

Ok got it, the OP wasn't asking about the adjustable valve, just his OEM distribution block/valve assy. I guess mvh's mustang reference steered me off course.
Anyway my sources do claim mustangs and others were equipped with the valve shown in the pic you posted. It is adjustable and was placed in the line leading to the rear brakes. I'm not sure its visible when looking under the hood.

hemi71x said

Anybody see anything "Adjustable" on an early Ford brake, proportioning valve?
Car manufacturer's didn't put anything like that on ANY of their cars.
Can you imagine some Bozo, messing around with something adjustable, on their car, and then getting into a wreck, with no brakes.
Car manufacturers didn't use anything like that, at all.

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