the rear beam on the 4x4 is narrower where the diff mounts i just remembered.if you are using the 4x4 beam and 2wd diff you need to shave a tad from the top mounting hole of the diff.easily dont but the diff will need some washers if it ever goes back into a 2wd beam.sure the hubs are the same,cant see any reason why they would be.i had some 4x4 rear hubs and flanges,sold them to a guy with a 2wd,remember him saying they would fit.never heard back so they must have.