This is a big body posi unit #761 , it has 12- 7/16 left hand thread ring gear bolts , was a 2:73 ratio unit , pinion # 409638-11 . Asking $250 plus shipping from zip 60034 , Hebron Illinois .Come with the 2;73 ring and pinion , they look good . This a 31 spline bolt in retained axles setup .