Developed directly from its model HD-20 (introduced 1951), the HD-21 featured among other things, one of the diesel engines from the recently acquired Buda Engine...
In production for just three years, the HD-20 was the stepping stone between the powerful HD-19 and the very successful HD-21. RICHARD CAMPBELL delves into...
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....