1 ton brake booster up grade questions...

[elks]

I am starting my swap and getting parts tomorrow. When I took the old booster off, there was no clearance between the top of the lever and the fire wall where it attached to the piston rod for the master cylinder.... What should it be?

Also before the swap the brake pedal would not budge, and the piston would not move back in. Now that it is off is would pump.... Is it possible or likely that the whole thing got in a bind? Anyone have it happen?

Also what vacuum pressure should I be getting at the booster? Just want to make sure it is good and not needing attention as well.