176-8542 SD70ACU Diesel CP Military Heritage 7021 BeigeIn many ways, the SD70ACU is a modified SD90MAC. The SD90MAC struggled to find a place on US and Canadian Railroads in the 90s. While Union Pacific and Canadian Pacific purchased many of these engines smaller railroads felt alienated from the gigantic prime movers which limited the SD90MACs operational use. In 2016 Norfolk Southern decided to convert several SD90MACs to SD70ACUs, the Siemens tech was swapped with Mitsubishi components and the cab was