Check out this site if you would like a Getrag to rebuild or just for a core. BGilbert it is even in Indiana.
http://cgi.ebay.com/ebaymotors/Dodge-Cummins-Diesel-Getrag-5-Speed-Transmission-Broken_W0QQcmdZViewItemQQcategoryZ33733QQihZ017QQitemZ270082974240QQrdZ1