Here is a look at the outside of the pinion housing-notice the bulged section of the casting; this is the upper lubrication channel as described earlier. The exterior of the housing features additional webbing in key areas for added strength. Notice the four holes on the top portion of the housing. These are designed to provide a footing for a fabricated steel bridge that makes mounting upper link mounts much simpler. Another thoughtful aspect Currie included in the design of the Iron Jock series is equal size pinion support bearings. Where most other differentials feature smaller bearings of different sizes, the Currie unit has two massive bearings of the same size.