This is a model for perfect how to instructions.
Question from a noob. Is this mod done solely for the look? I do like it. Just curious. Ty
No, there are several real good reasons to replace the factory differential cover. First and most importantly, the factory cover does not have a drain plug. That makes servicing the differential with new fluid real problematic. All fluids age with use and time, and the differential gear oil is no exception. All replacement differential covers have drain and fill ports because it's senseless to not have both. The Ford engineers evidently saved two ounces and $1.95 by not including a drain plug.
A second benefit is capacity. I've forgotten exactly how much more fluid the Mag-Hytec differential cover holds, but I think it's at least a quart more. More fluid in a differential is a good thing - it'll provide better lubrication over a longer period of time.
A third benefit is cooling. Almost all of the aftermarket differential covers are engineered with vastly greater surface area to draw heat out of the unit. As the differential is in the wind, it can't help but reduce the temperature of the gear oil and therefor the mechanical parts inside the differential. Heat is the enemy of both mechanical parts and fluids, so this is rea benefit especially if you do a significant amount of towing or hauling.
A fourth benefit is the dipstick in the Mag-Hytec differential. If there's any guesswork involved in refilling the differential to the proper level, the dipstick eliminates it.
And finally, both the dipstick and the drain plug have magnets. A magnet acts as an open filter, attracting and taking out of the gear oil any metal that may have accumulated due to normal wear. That keeps the fluid cleaner longer.
Convinced? You should be!