That's open to opinions, and there are a lot of them. In our converter shop, their opinion, shared by other converter rebuilders, was the original slotted factory hub was not hardened. As part of our rebuild, all converter hubs no matter what the make were changed, and no matter what they looked like. The hubs we used were hardened. Some transmission rebuilders like to use a bronze bushing instead of a babbit bushing in the pump and bronze bushings on the early softer hubs could/would cause premature wear on it. Again like I said in my opening there are many different opinions.