A one-off and very unique rebuild was NS 2423, a MP15E conversion. This unit featured a 2100 horsepower turbo charged 12-645E3C, R10 alternator, and was rated at Tier 2+ emissions. which required the unique carbody modifications. At the time the unit was testing in local service in and around Rose Yard in Altoona, just a stones throw away from the Juniata Shops. The program was never duplicated and NS 2423 remained in this configuration until it was sold in November 2019 to Midwest Rail (MWRX).