Prolly talking about the axle bearing seals. The diff lube travels up the axle tubes and lubes the outer bearings on these models. Seals keep lube from dripping into brake drums. For flange gaskets: depending on model, either reuse the old flange gaskets, cut new ones out of gasket material, or use silicon in place of gaskets.
While you have axles out, check them for signs of twisting or damage from seized bearings. No use rebuilding the R/E if the axles are gonna twist apart.
