Nice find - it looks like you got part number 10815. It's the only aftermarket cover I've heard of that fits the 4-link suspension vehicles without interfering with the anti-sway bar. It is pretty pricey compared to most common aftermarket covers. It is a nice, sand-cast part, though.

 

YA...Not much option other than OEM. I actually ground down the bottom cooling fin as there was a chance it would make contact with my aftermarket sway in extreme circumstances. As mentioned theer is 3.125" of clearance to the panhard/sway and this one is 2.83". I wanted something stronger than the OEM and a little more fluid...just another piece of insurance!