[sick472]

I'm new to power brake troubleshooting and not even sure if I have a problem. The truck just hit the road and the brake pedal seems stiff to me. It stops the truck fine and I can lay into the pedal an lock the wheels, but it takes a lot more leg muscle than my 85 K20. So much more that when I drove the 72 for a week and then hopped in the 85...I about threw myself through the windshield.

Where should I begin looking to make an improvement?

Note: It has a new master cylinder, prop valve, and 11" booster from GMC Paul's with stock 72 front disc brakes.