Hot Rods Brake Plumbing info needed.

Greetings all,I dont remember if I asked this question here before or not so here we go again.I have a 1948 Austin Panel Van.Im ready to plumb all the brake lines.I have a GM Prop Valve,172-1353.My M/Cyl is UNDER the floor and LOWER than the Prop Valve.I know I need a 2 lb RPV in the FRONT brake lines and a 10 lb RPV in the REAR brake lines.Do I need/Should I use an ADJUSTIBLE Prop valve in the REAR brake line or just plumb as I described .Can I use a ADJUSTABLE Prop Valve WITH the GM 172-1353 Valve OR IN PLACE of the 172-1353 Prop Valve.How would you Brake line plumbing Experts plumb this vehicle?Ive read that I CAN NOT use the GM PROP Valve TOGETHER with an Adjustable Prop valve!?What can you tell me?Thanks.

 

I would just use the adjustable valve.

 

Use only the adjustable or none at all if you have your system designed right

 

The residual pressure valves are also pressure rated for the type of brake, not for front or rear. 2 pound for disc calipers and 10 pound for drums. I would just use the adjustable one since I had read on this very forum that the GM style combination valves are all rated different but look exactly the same. Hard to know whats in your hands if thats the case.