both master cylinders that i have used are dual resevoir. the parts replaced are new wheel cylinders for 11" drums, new hoses, new brake lines, new springs, new Praise Dyno ceramic-metallic shoes and spring hardware. early b-bodies never had porportioning valves. the single resevoir master cylinder fed into a block that tee'ed out to the front and rear lines. i have never used that system. the Fine Lines conversion doesn't use any porportioning valve, it just simply splits the front and back. i thought my statement of parts in use was covered, maybe i wasn't clear, .