GP38AC 646 and U25B 808 by Frisco.org Posted on November 1, 2015 GP38AC 646 and U25B 808 GP38AC 646 and U25B 808 at Memphis, Tennessee in May 1976. This entry was posted in RT Collection and tagged 646, 808, Electro-Motive Division, General Electric, GP38AC, U25B. Bookmark the permalink.