The EMD SD70 was never in Conrail's plans. At the time of the sale of Conrail to the Norfolk Southern and CSX Transportation, Conrail was taking delivery of an order of SD80MAC's from EMD. Conrail was to eventually acquire 108 of the SD80MAC's.
Neither the CSX nor the NS owned SD80MAC's, so the order was canceled. The NS and CSX changed the order to have different EMD models built to their specifications. The NS ordered 24 SD70's with their portion of the order. True to NS practice, the SD70's are conventional cab, D.C. powered, bargain priced workhorses. They are numbered sequentially after the NS's fleet of 57 identical SD70's.