GMC C/K History

The C/K nomenclature — "C" for conventional two-wheel drive, "K" for four-wheel drive — was developed by GMC and applied to GM's full-size pickups from the 1960 model year (1962 for GMC's badged version). It ran across four generations through 1999 for the pickups, shared between Chevrolet and GMC with the GMC trucks positioned slightly upmarket.

The GMT400-platform fourth generation (1988–1998) introduced the more aerodynamic "GMT400" body and seeded the Sierra name. For 1999 GM replaced the C/K pickups with an all-new line and made the C/K name Chevrolet-only; all GMC pickups became Sierras, ending the badge's run on GMC trucks.