73 and up A-bodies don't even use them. I let Chrysler design the last system on the car I converted. I just used everything front to rear from a 75 Dart.
The junction block is actually a combination of the junction block and a porportioning valve.
I also did a disc brake up grade on my 73 Duster. I installed a pv, but it's set at wide open as my 295 / 50- 15's never lock up either.Yes I have no p-valve. But I have 295/50-15s out back and small wheelcylinders. It is possible to balance the system without one. I bought an adjustable one expecting to have to use it, but never required it.
This is the BEST way to do it: vary rear wheel cylinders or vary the pad & shoe materials. Using a prop valve of any type with a spring loaded piston (that doesn't self-adjust with brake pedal force) to bleed off pressure always is a compromise at some point as brake pedal force is varied. (But this is more than most folks want to deal with.)Yes I have no p-valve. But I have 295/50-15s out back and small wheelcylinders. It is possible to balance the system without one. I bought an adjustable one expecting to have to use it, but never required it.