I used a 1st gen dodge 4wd cross member for my Cummins swap. Just take the rivets out of the dodge, get the cross member/motor mount, and it will weld right into the frame of the jeep. I've done this twice now, because it was to close to the fire wall the first time.
Here is a pic of how good it fits in between the frame. Like it was meant to be!! Also note that I have spring over.
http://i1097.photobucket.com/albums/...psynlgdmaf.jpg