Proportioning valves are required for disc brake applications. The proportioning valve you need depends on your set-up. We offer proportioning valves in our kits, as well as sell them separately for all your needs.
USPS Priority shipping Flat $8 on these listed proportioning valves
PV-2 (disc front, drum rear) PV-2 diagram pdf $55
PV-4 (disc front, disc rear) PV-4 diagram pdf $55
PVC-B (adjustable) PVC-B diagram pdf $75
(diagram for informational and reference use only)