Oh man, I remember when I did mine... The passenger side was fine reusing the old hub, but when it came to the driver side, it instantly killed the new bearings because the hub turned out to be bad as well, which basically made the job harder 'cause I did it twice on that side. Now I have an extra wheel bearing and a hub from a 300 which has a smaller dust shield compared to the SC400's.
I'd suggest buying a new hub too, just to make sure the old one is bad. Only thing that's gonna make things complicated is, only way to find out if hub is also bad is after installing it in with the new bearing to see if there's still "play".