The defense , led by Jack Lambert , Mel Blount , Jack Ham and Mean Joe Greene , gave up fewer points than any other American Football Conference team in Pittsburgh 's Super Bowl seasons of 1974 and 1975 . The unit , led by Jack Lambert , Mel Blount , Jack Ham and Mean Joe Greene , gave up fewer points than any other American Football Conference team in Pittsburgh 's Super Bowl seasons of 1974 and 1975 .