No sir, not a prop valve. This was a drum/drum car, they just had distribution blocks. Not a proportioning valve like the disk/drum cars. The block and the adjuster to the rear will be just fine.
You know it probably doesn't matter. Mopars of this vintage did put the residual valve in the master. Other makes put them in the prop valves. I've converted a couple of drum/drum cars with modern master cylinders and prop valves and I just put the residual valve between the brakes and the prop valve. Keeps it under the car so you don't see it in the engine compartment.
Yeah, the brake switch isn't for the lights its for the warning light, I was just thinking it's a pressure switch so adding the residual valve so it would hold pressure through the switch could change it's function if it wasn't intended to see the residual pressure. But I forgot that the originals had the valve in the master.
