well on mine with mikes losi 8 motor mount.......it has a groove that holds the bearing that over the drive cup shaft...well on my center diff the front drive cup had a larger bearing than the rear drive cup......so when I turned the diff 180deg the bearing was too large to fit in the groove on mikes motor mount...hence having to take the diff apart and switch the bearings.......maybe the guy I bought this eight from had different size bearings for some reason

anyway tomorrow I will post pics of this conversion