Chevy Square Body Years: How to Tell 1973-1987 Trucks Apart

What "Square Body" Actually Covers

Chevrolet's third-generation C/K trucks arrived for 1973, and the hobby nickname "square body" stuck to them for good. In the naming system, C meant two-wheel drive and K meant four-wheel drive, while 10, 20 and 30 marked the half-ton, three-quarter-ton and one-ton classes. So a K10 is a four-wheel-drive half-ton, the sibling of the C10. GMC built its own versions on the same sheet metal. Wikipedia counts the generation as running 1973 to 1991, with the later years carrying the R/V badges described near the end of this guide.

1973-1980: The Early Face

Early trucks are told apart mostly by their grilles, because all of them rode on the same basic front end. For 1973 and 1974, Chevrolet used a recessed grille with orange turn signal lenses. For 1975 it switched to a flush-mounted grille that looked brighter, and the Scottsdale and Silverado trim levels joined the lineup. Displacement decals came off the grille for 1976. A larger-segment grille arrived for 1977. For 1979, a minor facelift painted the vertical grille bars dark gray and moved the turn signal lenses into the chrome trim.

The truck on the left in the render shows the look that defines this stretch: two round headlights, each set into a chrome bezel, behind a boxy grille. Round lights are the quickest sign of a 1973-1979 truck, and 1980 is the wrinkle. For 1980 Chevrolet gave the truck an all-new grille, and Wikipedia says square headlights debuted on Silverado models while lower trims wore the 1980 grille with the 1979 round headlight surround. Owner forums and parts listings disagree on exactly which 1980 trims got which lights, so treat a 1980 as the changeover year and check the truck itself before ordering parts.

1981-1987: The Facelift Years

Chevrolet reshaped the front of the truck for 1981. According to Wikipedia, the hoodline dropped, the wipers became exposed, and the grille was split by a bar of silver and black on Chevrolet trucks, while GMC's grille was divided into ten squares. Square headlights became standard, with two on base trims and four on upper trims, though owner forums describe the four-light setup as an option on some trims, so trim alone is not a guarantee. Fender badging switched to block lettering, which lasted through 1987.

The close-up in the second image sets the two eras next to each other: a round lamp in a chrome bezel on the left, two stacked rectangular lamps on the right. That quad look is what many people picture when they hear "square body."

The facelift years also had small steps of their own. For 1982 a chrome bumper and a chrome-trim grille became standard, diesel trucks got their own fender and tailgate badges, and Chevrolet dropped the Cheyenne line, largely folding it into the Silverado. Wikipedia adds that the two-headlight setup was dropped for 1983 and returned on base trucks for 1984, so the light count shifts within the facelift years too. The grille changed for the last time in 1985, when two-tone Chevrolet trucks got a body-colored grille center.

Trim Names and the GMC Twins

Chevrolet's 1973 lineup ran Custom, Custom Deluxe, Cheyenne and Cheyenne Super. From 1975, Custom Deluxe became the base trim, Scottsdale sat in the middle and Silverado topped the range. GMC started 1973 with Custom, Super Custom, Sierra and Sierra Grande, then made every pickup a Sierra for 1975, in Sierra, Sierra Grande, High Sierra and Sierra Classic trims. Grande was dropped in 1982. The easy way to tell the brands apart from the front: GMC's grilles were divided in thirds in 1973-74, then six segments from 1975.

Inside the Cab

The dash is a quieter clue. Wikipedia says 1973 to 1977 trucks used chestnut woodgrain inserts on the dash and doors, and from 1978 through 1987 those inserts were brushed aluminum. Seats, door panels and the dashboard were updated again for 1981. The interior render above shows a worn bench seat, a large steering wheel and a wood-look dash panel with a dirt road beyond the windshield. It is an imagined scene, so use it as a mood reference, not a year guide.

1987: When K10 Became V10

For 1987, GM began replacing the Rounded Line with the new generation, which was launched in April 1987 and sold officially as 1988 models. The outgoing trucks were renamed the R/V series, with R for two-wheel drive and V for four-wheel drive. That makes a 1987 half-ton four-wheel drive a V10 on paper, and auction listings do use that name, though most owners still call it a K10. The new trucks carried the 1500 naming for 1988, and the old R/V trucks switched to 1500, 2500 and 3500 numbers in 1989.