What years are considered square bodies?
The square-body era refers to GM's full-size pickups from Chevrolet and GMC, produced with the boxy sheet metal between model years 1973 and 1987.
Definition and timeline
In automotive slang, "square body" describes the GM C/K pickups and their Suburban relatives during the 1973–1987 generation. The look is defined by squared-off fenders, flat panels, and a distinctly boxy overall silhouette that stood in contrast to earlier, more rounded designs and the later 1988 redesign. The era encompasses both two-wheel-drive and four-wheel-drive variants as well as different trim lines that shared the same fundamental body shell.
Design cues that define the square body
Several visual elements help identify a square-body GM truck at a glance: a boxy, angular exterior with squared-off wheel arches; a cab and bed that align in straight lines; and a cabin interior and dashboard style common to the period. While minor changes occurred over the years, the overall silhouette remained distinctly squared throughout the 1973–1987 window.
Key milestones within the era help observers and collectors identify model years at a glance:
- 1973: All-new body style with squared-off fenders and flat panels; start of the square-body era.
- 1974–1979: Continued production with incremental mechanical updates while exterior geometry remains square.
- 1980–1982: Mid-cycle updates across some trims, preserving the square silhouette.
- 1987: Last model year of the square-body generation before the 1988 GMT400 redesign.
The list above outlines the core window and evolution within the square-body era, illustrating how the design persisted across nearly 15 years of GM trucks.
How to identify a square body today
People interested in classic GM pickups use a set of visual cues and documentation checks to confirm a vehicle's square-body status. Look for the recognizable square-off panels, era-specific grilles and cab geometry, and corroborating VIN/model-year data.
- Boxy fenders and flat, angular body panels that give a squared-off silhouette across the vehicle.
- Cabs and bed rails that align in a rectangular geometry rather than rounded shapes.
- VIN 10th character or other model-year stamping indicating a year within 1973–1987 for GM C/K trucks or Suburban from that generation.
- Interior styling and instrument panels consistent with late 1970s to mid-1980s GM design language.
Recognizing these cues helps buyers and restorers determine whether a truck belongs to the square-body period and informs parts compatibility and value.
Summary
The square-body GM C/K trucks represent one of the most recognizable boxy-era pickups in American automotive history, spanning model years 1973 through 1987. The era is prized for its simple, rugged design and a large ecosystem of parts and knowledge that persist among collectors and enthusiasts.
