Braking problems

As to the pushrod length;
If it is too long, your booster will activate very early in the pedal travel making it hard to modulate the braking.
If the M/C was properly bench-bled, and just swapped over after the rest of the system is functioning properly then everything else works normally, for a while. But the too long pushrod will not allow the piston to park properly. Two things are gonna happen; 1) the brakes may not/will not fully release, and 2) over time, as the pads and shoes wear, the pedal will drop continually lower, for lack of compensating fluid entering the system.
But if you try to bleed a system with a too long pushrod, that does not compensate, almost immediately you will know that something is wrong because, after the first pump, no more fluid comes out when your helper pumps the brakes.
If the rod is way too long, you could break the control valve on a panic-stop, rendering the booster garbage.
If the rod is too short, the first portion of the pedal travel will be taking up the slack, and it will take excessive pedal travel to get the braking done. Brake boost may come on too early

It is easy to prove the C-port is working; just shine a light down into the reservoir, at the C-port, while a helper very slowly steps on the pedal. You should see the fluid roiling as the fluid backs up into the reservoir. Close the lid and clamp it before your helper allows the pedal to return, as sometimes if you have air in the system, it can push the fluid back rather violently creating a geyser that can hit the underside of the hood,and then drip down everywhere; and you know,
most brake-fluids eat paint.

Ok I think I got that right