Brakes!!!!!! 67 c-10 lwb

[ables477]

Okay, I have a 1967 C-10 LWB with a 283 (pulled from an Impala), 3 spd on floor.

Everything runs great, just no brakes. Makes it difficult to drive. I have replaced the master cylinder 3 times, new stainless steel lines from inline tube, new rubber hoses up front, new wheel cylinders on all four wheels (drum), and a used proprotioning valve.

I get excellent pressure to the front brakes, but nothing to the rear. I would have to guess that the proportioning valve is bad? I think that the second fluid resivor in the master cylinder is a reserve correct, not for the rear brakes.

Can I replace the proportioning valve with an aftermarket proportioning valve? If so which one? I have noticed that most of them say disc-drum and disc-disc. My truck is a drum-drum. I just want to get the thing on the road without going broke. Help!!!!!!