Interesting brake problem, what is a good pedal?

[andymarkv]

Hey guys!!
The 71 C20 I'm working on has had a very hard brake pedal since the first time I've driven it. Is this normal?

I replaced the calipers and front brake hoses, the pedal was till hard and didn't stop well. (even though the calipers were close to stuck)
I replaced the booster and master cylinder (19" of vac to the booster) and checked for binding in the brake pedal movement, still hard pedal doesn't stop well.
Changed the proportioning valve with a stock style one, I believe it is bled correctly, there isn't a brake light on, tested for continuity at the switch post (its open), the rear brakes don't lock and the pedal is sill hard and doesn't stop well.

My father in-law says that it takes a little more effort than he is used to to push the pedal to bleed the front brakes, but if he pushes with medium effort I get great fluid return out the bleeder.
What the heck is going on?!?!?!?!?
I've never heard of blockage in the steel line or Y block that separates the left and right front brakes?

Or do 67-72 Chevy truck brakes just stink, like the 99-04 Silverado's have a mushy soft pedal even when working correctly?