Wondering if anyone can help with info disc brake prop. valve.

Just bought a used Kelsey Hayes disc brake kit for a 65-72 a body and got the disc brake proportioning valve w/o lines in the pic. Sitting in my parts bucket is the valve with all the lines still attached. The only car I ever remember parting with disc brakes was a 70 satellite with factory single piston disc brakes. I know it's a b- body but does anyone have any info or experience with this.
71 duster valve has k/h 141-0 x, the other has k/h 155-0 x so both are Kelsey Hayes.

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