Classic MachinesTractorsClassic Machines: The Allis-Chalmer’s HD-14 tractorContrafed PUblishingFebruary 26, 2016September 13, 2021 by Contrafed PUblishingFebruary 26, 2016September 13, 2021 The Allis-Chalmers HD-14 was introduced in 1939 and was broadly based on that company’s earlier and very successful Model L and LO gasoline powered crawlers....