8.75 A Body rear end housing

The guy that narrowed mine uses a long tube through the rear end housing to keep everything straight. A bare 489 case is bolted on and 4 "pucks"(don't know exactly what you call them) are placed in the axle housing. One on each end and two in the center section. The tube is slid through all four pucks to hold it straight while the ends are welded back on.