For decades, Perkins has been restoring the machined look to the rear axle “chunk.” Over the years, this bare metal develops surface rust on driver Mustangs. Rear axle housings frequently have runs in the semi-gloss black paint. The yoke (top) is unpainted. The pinion nut is daubed with yellow paint. The outside of the centersection is red epoxy primer (tinted Ditzler DP-74) with a shiny, machined surface and features heat-treated bolts tightened with zinc dichromate plated nuts backed by copper washers for sealing.