WTB 73 + disc/drum proportioning valve

The valve/block pic hemi71x has posted is a disc brake proportioning valve that was started to be used in 1971. Prior to 71 a block and a seperate prop valve was used. The mopar drum block pic #2 was used for drum cars. Disc brake cars used the drum block pic #2 and the pic #3 prop valve. In 71 the valve was consolidated into one valve. You can see how the #3 pic prop valve was amalgamated into the drum valve.

The first pic is a 71 and later proportioning valve for disc brake cars
Pic #2 is a drum block for drum cars when used by itself
Pic #3 is a proportioning valve for disc brake cars 70 and earlier when used with pic #2 block.
the Prop valve ( pic 3 )was mounted 12-14 inches away from the drum block and was mounted on the side of the frame rail almost under your feet.

The disc block Pic #1 was used till at least 1975.

Finelines sells the one piece proportioning valve too. Ask for RBV002. Marcel.