The line hardly ever stopped at the Cadillac engine factory during wartime. Hundreds of new, big V8 engines were crated up each week for use in Stuart tanks. The same goes for General Motors and their never-ending line of newly-created Hydra-Matic transmissions. Two pairs of the powerplants and gearboxes went into each M5 Stuart.
However, as the war moved into its final years, it became clear that the Stuart was obsolete (compared to the Sherman, Chaffee, and others). Now what to do with all that perfectly good horsepower made for a now-defunct tank?
The switch was made easy when the LVT-3 Bushmaster amphibious assault vehicle design got up and running. Each LVT has a set of Stuart engines and transmissions installed, one pair in each sponson on either side of the cargo bay. In the water, the transmission only had first and second gear. On land, the LVT-3 had four speeds (and reverse) and could move at up to 17 miles-per-hour.
Cory Graff is the military aviation curator at Flying Heritage Museum.