Master Cylinder???

I've always used a manual for a "75 plymouth valiant" on 3 different conversions. 1 factory and 2 scarebird. Bolts on with the same 4 bolt pattern and uses your same pushrod. The only mods may be for you lines. I plumb the fronts straight to the big reservoir and an adjustable prop valve inline to the backs to adjust bias.

So, you just ditch the factory prop valve and 'T' the front line. Then just use an adjustable prop valve for the rears? Seems easier than buying the 'correct' proportioning/distribution valve. I can't seem to find those for any less than $100 anyway. Do you know a good source for them, before I pop for an adjustable one from summit???