What B-bodies used the same width 8.5" housing as the 9C1/Impala SS disc brake equipped cars? I am wondering because I am scouring for a second rear end that I can rebuild to stick into my Caprice without loosing the use of the car. The RoadMaster's have a narrower rear diff than my 96 Caprice does I gather, correct? If I find an LT1 Civilian Caprice with drums is the differential housing the same width?