Don't know if this will be any help but......I've had more than my share of problems with trying to adapt factory combination/proportioning valves to project vehicles. Without going into a novel about the problems I encountered, I'll just cut to the chase and tell you how I set up my systems now.
Dual master, adjustable proportioning valve (Summit SUM-G3905, $35.95) 2 (if using front discs) & 10 lb residual valves. The prop valve goes after the 10 lb. valve in the rear circuit. You've got your rear shoes dragging slightly.....open the valve up completely, bleed all circuits, crank valve down to full closed and back off 2 turns for road test. Don't forget to readjust your rear brakes. You may have to make final tweaks to the adj. prop. valve depending on your particular driving habits.
The "pin" that was used in FoMoCo valves required a little clip that would hold it out during bleeding process and I've had to remove the guts from other valves to get them to bleed. The adjustable prop valve will eliminate your problems.
Dave
Last edited by Fla54Chevy3100; 12/11/2007 2:24 AM.
