Are you referring to play in the U-joints or the wheel bearings?
1973 L-82 4 spd
At the dust covers at differential
I think there is side play associated with the differential gears. This is my first rebuild of C3.
Since you are rebuilding the differential then I suggest you get a copy of the factory service manual which will have the specs on the side play.
1973 L-82 4 spd
Maybe call Bairs, they overhaul rear ends.