We did something a little different for adding a rear crossmember to the relocated shackle hanger location for the 63's at the end of the frame..  Incorporated one into the rear bumper for final welding at final assembly time.  While adding this cross support I though I'd add a little more support to the receiver as well.  In doing this I was able to make use of the void where the stock spare would sit.  We now have an ideal location to insert anything we want into the inner side of the receiver to be stowed up tight under the rear of the rig.  For example, the thought of 36 volt welder comes to mind.