First hand experience with changing to the NBS master cylinder WOW!

[Tom]

Originally Posted by Red88

Bled system and found firm pedal but less braking power. No good!

Originally Posted by Red88

This is all about increasing the area of diaphram and thereby increasing the force applied thru the booster to the master cylinder and reducing the amount of pedal force needed to stop the truck.

I'm confused. You didn't have less braking power with the original booster and NBS master. You just needed more pedal effort, which is the entire point of the swap. You changed the master cylinder to get a firmer pedal, then changed the booster style to get a less firm pedal? Sounds like you just needed a correctly functioning OBS master and 10.75" booster to begin with... Your diaphram research and pictures are excellent btw!