After receiving the class I motors, the Portland Shops signed an agreement with EMD to have them manufacture the electrical components & trucks for smaller motors that used ABB drivetrains drivetrains. The class J roadswitchers were one of them, and the class K were another; the class K used a drivetrain much like the ones that were in GMD’s GF6C motors, EMD’s (ABB-derived) articulated radial trucks, and Portland carbodies.

Six were built (three streamlined, three steeplecabs) and they all remain in service in 2024.