Any help on connecting my XJ6 master cylinder's 2 outlets to the 5 ports on the proportioning valve would be greatly appreciated.
Of the 5 connections on the valve 2 are smaller, closer to the end nut and 2 bigger with one on the end. Are the smaller ones perhaps for the rear wheels?

Im using the full Jag brake setup in my Cobra hence the need for the proportioning valve
Rescued attachment proportioning valve1.jpg

Looks like a hydraulic circuit failure warning light switch to me. it has a little shuttle inside that moves operates the switch when there is a pressure differential across the valve.