I'm in the middle of rebuilding my brakes, so I have a tip sheet from PJ
Grady. It sounds like it might be the answer to your problem. He didn't
put a copyright on it, so since it's a safety issue I'll do an OCR scan.
For using his tip sheet, I'll be a shill too: His rebuilt brake calipers
and master cylinder are top quality. They are beautifully zinc plated to a
golden color. They have all the top quality stuff in them that you won't
get from a regular auto parts store.
This new brake master cylinder often requires adjustment of the brake booster piston rod to avoid extra pedal travel when braking. If after installation and proper bleeding you experience a low pedal remove the two 17m mounting nuts and pull master cylinder away to allow access to booster (you can leave brake lines attached) adjust booster rod using 8m socket wrench to adjust rod. Have someone depress brake pedal or use appropriate length bar wedged against seat bottom to allow access to booster pin and hold with pliers while adjusting 8m rod setscrew. Mark socket with a black magic marker and turn rod counter clockwise to lengthen. Usually two to three full turns are required to give a good solid pedal. There should be at least 2" of pedal travel before brakes apply or dragging and subsequent rotor damage may occur. After adjusting road test car and then check wheels for brake dragging before you're done.