This is the 726 Olds axle posi for the bolt in axles from 1973 to 1977 . It has the 2:56 ring and pinion with it , it fits the 2;41 or 2;56 ratio ring and pinion . It was removed to go to the 3:73 set up . Worked good before removal . Asking $150 plus shipping from zip 60034 or picked up at my location in Hebron Illinois .