I swapped a late model AAM 14BFF with factory disc brakes under my 1972 K5 Blazer. It came out of a 2005 GMC 2500HD truck. There are two versions, one with a 10.5" Ring Gear and an 11.5" Ring Gear identified by if it has a weighted ring on the input yoke. The new axel is wider than original and will use metric brake line fittings and wheel studs. I had to remove and replace spring perches and shock mounts on the axle tube. I used aftermarket E-brake cables.
www.car-part.com