Hi mate, i remember asking my self the same question when i rebuilt mine, in the end i decided to go with the standard washers as long as the bearing are properly pressed into the case (giving the same height) and you are using the same diff and casing there isn't a lot else to change IMO.

From what i know you dont want any end float, the spring washers give pre load to minimise/eliminate end float. I would be concerned if you could move the diff in and out, and less so if the diff seems a little stiff. How stiff is stiff?

Any how, mines spot on so far.

Rob,