Early in its production life, the 3900 was widely used in the school bus industry by body manufacturers as a replacement for the General Motors S7 and the Asia Smith chassis. In 1993, both Carpenter and Wayne Wheeled Vehicles both switched chassis suppliers, leaving AmTran and Canadian manufacturer Corbeil as the sole users of the 3900; Corbeil switched to a rear-engine design before abandoning production of Type D buses for good in 2000. Corbeil's transit-style buses (nor any of their other full-size offerings) were never sold in the United States. Buses produced on the 3900 include: