 The SD49 was advertised but never built and a total of 9 GP49s were built.Alaska Railroad is the only company that ordered it in two orders; the first was ARR 2801-2804 under order number 837049-1-4, built in September 1983 and the second was ARR 2805-2809 under order number 847035-1-5, built in May 1985.Six GP39Xs were built in November 1980 for the Southern Railway under order Number 786284-1-6 and upgraded to GP49s shortly thereafter.