Our rear Dana was out of an ’87 Chevy and used a keyway and snap ring (A) to lock the axle hub nut down. We’ve seen issues with these and we were missing some parts anyway. Our old Dana 70 used hex nuts (B) and was a common way to hold hubs on 20 years ago. The problem with them is that they require a thin-walled socket to install and don’t leave much space between the nut and hub to work in. The parts on the right (C) are the current parts that Dynatrac uses and is our favorite setup for retaining hubs.