Its hard for someone like CPP to know all the various OEM components their kits might be matched with, and since the needs of different truck owners vary it doesn't make sense to limit the options to just one master cylinder or a short list of possible masters.
Adapting the kit and instructions should be part of our expectations when tackling a project like this.
I know its frustrating and we always want the kit to fit exactly our individual truck and needs, but its not a realistic expectation.
I have the CPP bracket on my '55 1st Suburban. I had trouble with the alignment of the rod and ended up leaving off the retainer on the pedal pivot. Since both come through the floor and are on that pivot and attached to rods on the other end, they don't seem to move far enough for it to be a problem except in the occasional hard corner when the brake pedal will stick a little coming back up.
Not perfect, but I've been driving it that way since late 2002 and have been satisfied.
My next moves with this truck will probably include a firewall mounted booster and that will change the whole thing.