What is the difference between C and K in Chevy trucks?
In Chevrolet's full-size pickup lineage, the letters C and K identify drivetrain layout and class, not trim or engine. C-designated models are two-wheel drive, K-designated models are four-wheel drive, with the numbers indicating approximate payload capacity. This naming convention was used on the classic C/K family from the 1960s through the late 1990s.
What the letters mean
The C and K prefixes appear at the start of the model code on the truck badge and in documentation. They tell you whether the vehicle was built for two-wheel drive (C) or four-wheel drive (K), while the following numbers denote the payload class. This scheme was shared across Chevrolet and GMC full-size pickups in that era and remains a common way historians and collectors refer to the era.
Practical examples
Common C/K codes you’ll encounter on badges and listings include the following:
- C10 — 2WD, half-ton
- C20 — 2WD, 3/4-ton
- C30 — 2WD, 1-ton
- K10 — 4WD, half-ton
- K20 — 4WD, 3/4-ton
- K30 — 4WD, 1-ton
These identifiers helped buyers quickly gauge whether a truck was suited for light-duty tasks, everyday driving, or heavier hauling. The C/K naming sits at the heart of GM’s long-running full-size pickup family, which spanned multiple generations and body styles.
Historical context and retirement of C/K naming
The C/K family first appeared in the 1960s and continued in various forms through the late 1990s. In 1999, GM shifted to newer platforms and adopted the Silverado (Chevrolet) and Sierra (GMC) branding on the next-generation pickups, moving away from the classic C/K badges. Today, the C/K designations are primarily used by collectors, restorers, and historians to identify classic GM pickups.
How to identify a C vs. K today
Enthusiasts and buyers often rely on badge cues and historical context to distinguish C from K models in the wild or in listings:
- Look for the model badge on doors or the tailgate, such as C10, C20, C30 (2WD) or K10, K20, K30 (4WD).
- Check the drivetrain indication on the badge or spec sheets: 2WD badges point to C-series; 4WD badges point to K-series.
- Note the payload class implied by the suffix (10/20/30), which roughly correlates to half-ton, three-quarter-ton, and one-ton configurations—though exact ratings can vary by year and market.
With older GM trucks, the badge and model code on the nameplate are the most reliable indicators of whether a truck is a C-series or a K-series. The VIN can provide year and body style information, but the C/K prefix is the strongest clue for drivetrain classification within this generation.
Summary
The C and K designations in Chevy trucks are historical indicators of drivetrain layout and payload class. C denotes two-wheel drive, K denotes four-wheel drive, with the following numbers roughly mapping to half-ton, three-quarter-ton, and one-ton capabilities. This naming system is tied to the classic C/K family, a staple of GM’s full-size pickups from the 1960s until the late 1990s, and now primarily of interest to collectors and enthusiasts.
