Rear brakes on 66 dart NOISE and stutter?? HELP

It is against the law to manufacture everywhere in the United States now for over 20 years -- but it is N O T illegal to transact
on product that was manufactured before those laws and statutes went into effect -- they are "grandfathered in" -- so it I S
perfectly legal for us to transact on it -- these are VERY VERY N.O.S. -- you can tell by the boxes themselves.....