At least it's something simple. I'm not sure on the part number. You should be able to find it at the dealer. Shouldn't be very expensive. When you put it back on, I'd recommend using some RTV on both sides of the gasket. The same gasket is used on the opposite side of the motor to seal the coolant after it goes through the oil cooler, and it leaked on my truck the first time I put it back together. Used some GM engine sealer RTV, and it didn't leak a drop after that.