Summer Bros. use to repair the inner carrier bearing race seat on the inner tube ends and provide a shim that went in between the race and the tube I have seen several Dana 60 that had spun the carrier bearing races and goof up the tube ends OP, look closley at yours for any signs before building it. As far as replacing the axle tubes I have a Dana 60-2 that has 2.5 tubes in it, I talked to Cass at Dr Diff to see if he could, would, remove and put new 3 inch tubes in mine as it was hit in a train wreck and bent the crap out of both tubes before I bought it. It was the front end out of 1 ton 4x4. He said no he didn't do them anymore due to wearing out the cutters on his lathe or mill while enlarging the cast steel housing that the axles tubes press in I was planning on that rear end being a really trick lightweight rear end for a four link project car, I was bummed when I found out it was a no go Maybe I will call Dutchman