[MDPotter]

What are your plans for the brakes? I have the same Astro van setup as you. I have stock rear drums and am doing a front disc conversion and I'm planning on using the Astro master cylinder and a residual pressure valve for the drums, but not sure about what to do about a prop valve yet.

I've been talking with GMC Pauls and they have a brake line kit which might match up with the Astro prop valve. The kit has a single 3/16" line to the prop valve for the front drums and a single 1/4" line to the prop valve for the drums. I was going to buy a disc/drum prop valve from Speedway Motors, but it has (2) outlets for the front so now I'm thinking about using the Astro prop valve.