Sure, but after 40 years he may also have never seen a car that braked optimally either. Stopping and stopping as quickly as possible are two different things.
Sending equal pressure to all 4 corners only works if the brakes are sized so their stopping power matches the braking balance needed for that car.
Typically the front brakes do about 70% of the braking, the rears do about 30%. But the exact percentage depends on the weight balance of the car, the tire size stagger, etc.
The distribution block was used by the factory, and it sends equal pressure to all 4 corners. But the factory calculated the brake force needed at all 4 corners and designed the brakes to provide that amount of force with equal pressure. They designed the entire system to work correctly that way.
Your aftermarket kit just used rear disks that are intended for a completely different car, with rotors that were cheap and easy to fit to an 8 3/4 axle. I seriously doubt the brake force was calculated and matched to the requirements of an A-body at all, let alone one with your cars particular modifications.
Like I said, is it possible the factory distribution block is “close enough” that your car won’t be a hazard to life and limb when you stomp on the brakes? Sure, it is. Is it likely that distribution block with no adjustment is going to give you the ideal brake force distribution and shortest stopping distance? No, not really.
