350/3500 series pickups - any improvement to the brakes?

I don't have the specifics you want but I did some reading about the standardized tow ratings J28xx and there was something in there about being able to stop the max weight in a certain distance, so braking actually is part of the uniform standards, now. Going from a 97 srw to an 03 dually was a BIG improvement. I hope brake improvements have followed the same curve as the power increases. It seems like they would have to, to comply with the SAE standards. Craig