Power Disc Brakes not working on hard stop?

My car has the SSBC power disc brake kit
What kit did you get - I just put one in a 67 RT - same issue. The kit I got was the A156-1 which came with the MC & Booster but very little if any direction. Had a faulty caliper which they replaced. I'm hoping this pin adjustment will work and it not just a limit of the system.