C/K is a series of trucks that was manufactured by General Motors from the 1960 to 2002 model years. Marketed by both the Chevrolet and GMC divisions, the C/K series encompassed a wide range of vehicles. While most commonly associated with pickup trucks, the model line also included chassis-cab trucks and medium-duty trucks and served as the basis for GM full-size SUVs. Through its entire production, the model line competed directly against the Ford F-Series and the Dodge D series (later the Dodge Ram pickup). Used for both the model branding and the internal model code, "C" denoted two-wheel drive; "K" denoted four-wheel drive. Four generations of the model line were produced, including the second-generation "Action Line" and third-generation "Rounded Line" vehicles. For the fourth generation, GMC revised its branding, changing to a singular GMC Sierra nameplate (C/K remained as an internal model code). For South America, the model line was manufactured by General Motors de Argentina from 1960 to 1978, Sevel Argentina from 1986 to 1991, and General Motors Brazil, who produced versions of the model line for Brazil, Argentina, and Chile from 1964 to 2001. As GM entered the 1990s, the company revised its truck ranges, replacing the medium-duty C/K trucks with the Chevrolet Kodiak/GMC TopKick for 1990. For 1999, GM replaced the fourth-generation C/K pickup trucks with an all-new model line; in line with GMC, Chevrolet dropped the C/K nameplate (in favor of a singular Chevrolet Silverado nameplate). Initially marketed with its successor, the final C/K pickup trucks were produced for the 2000 model year. From 2001 to 2002, the final vehicles of the C/K model line were heavy-duty chassis cab trucks. First generation (1960–1966) Launched in the fall of 1959 as a 1960 model, the first-generation C/K debuted a number of design changes for General Motors light-truck design. Replacing the Task Force range, the C/K was developed from the start as a truck chassis, no longer sharing commonality with the GM A-body platform. Though developed as a truck for the sake of durability, the C/K adopted several features from cars into its design to increase its functionality. For pickup trucks, the C/K trucks used a drop-center frame which allowed for a lower cab and lower center of gravity, and independent front suspension was paired with a coil-sprung rear axle. For 1963, front torsion bars were replaced by front coil springs (on two-wheel drive vehicles). While the