B-body Clutch/Brake Pedal Assembly

Are the clutch/brake pedal assemblies the same for manual brakes and power brakes? I've seen similar '71 B-bodies that both have power disc brakes, but the brake pedal on one car sits higher than the clutch pedal while the brake pedal on the other car is slightly lower than the clutch pedal. If they are interchangeable, what would cause one brake pedal to be higher than the other?

I believe the pedals are the same but the brake linkage is different with PB. That could account for the height difference.