Need M/C recommendation

[cheapta]

Hi-I haven't posted here in forever but I'm at my wit's end with my 69 Z/28. Years ago I installed 79 Trans Am rear discs on the car, it's factory 69 disc fronts. I tried using the factory 69 M/C-as you might expect, no pressure to the rear brakes. I than installed a factory 79 T/A master and, once again, no pressure to the rear brakes. I should state that I also have an adjustable prop valve plumbed into the rears. The third try was a 69 Corvette M/C and-you guessed it-no pressure to the rears. I pulled the M/C off the car this week-I also happen to have a C3 Vette project car so I pulled that M/C off for comparison purposes. The Corvette master mounted on the Camaro booster seemed to be bottoming out when the pedal was pressed, I could actually see the master move at the bottom of the stroke. Here's what I don't get-the holes in the Camaro and Corvette M/C where the pushrod goes are identical. Does anybody have a recommendation as to what M/C I should use? I haven't driven the car in probably 4-5 years because of this and I've vowed to have it working for next driving season.

Thanks,

Peter-