Kelsey-Hayes proportioning valve for A body

Hey Rob. That's the million dollar question. At this point I'm not sure if the newer style will work. Posted question regarding operating pressure. Awaiting a response. Did read about installing smaller rear wheel cylinders but not sure if my application is applicable.
Ok. Well, if you decide you need it, I have one. I used the style without the adapter on Vixen. That's what she has now, even though she still has drums all around. I went ahead and upgraded the hydraulics before I pit the discs on the front.