Cabover trucks were developed in response to laws that limited the overall length of trucks on the highway. By moving the cab forward and over the engine, the truck could be made several feet shorter, and the saved length could be added to the trailer instead, thereby increasing cargo space. The 1960 GMC cabover offerings included the aluminum-cab “F” series and the steel-cab “L” series. Although the aluminum-cab “F” models would be replaced by the Astro in 1969, the steel-cab models would continue production until 1981.
The Astro offered many improvements over the “Crackerbox” trucks. A larger cab provided more interior space and greater comfort for the driver, and larger windows allowed for better driver visibility. Upgrades to the truck’s suspension improved its handling and ride, as well. The Detroit Diesel engines that were available in the “F” and “L” series of trucks were joined by optional Cummins diesel engines in the Astro line, and the Astro was available with a wider range of engine and drivetrain combinations than the “Crackerbox” trucks had been.