The 800 series front axels hve remained unchanged since the fiveton trucks wer gassers. In seeing all the front end failures,It seems to me that the cause is the excess weight of the Cummins engines. Especially, since they were never beefed up since the early days. We just changed the front axel in the M816 from an 813 take out. It bolted right in. I suspect that the hubs and drums would be different if you swap an axel from a bridge truck. Just use your old drums and hubs. I'd pay attention to inspecting the bearings and repack them when you have it apart just to be on the safe side.