# Chevrolet C10 (Square body, third generation)
Source: https://fullysorted.com/research/models/chevrolet/c10-square-body
Publisher: Fully Sorted (fullysorted.com), collector car research
Last updated: 2026-10-01

## Key facts
- Make: Chevrolet
- Model: C10
- Generation: Square body, third generation
- Years: 1973 to 1987
- Body styles: 2-door regular cab pickup (half-ton C10, Fleetside and Stepside beds, 117.5 in short-bed and 131.5 in long-bed wheelbases), 4-door crew cab pickup (new for this generation, one-ton trucks at launch), Bonus Cab pickup (crew cab with the rear seat deleted for storage, from 1977), Dual-rear-wheel one-ton pickup (Big Dooley)
- Engines: 250 cu in (4,097 cc) inline-six, Monojet carburetor, 100 hp for 1973 per Hagerty and 105 hp per Wikipedia, 185 lb-ft; replaced by the 4.3-liter V6 for 1985; 292 cu in (4,785 cc) inline-six, 120 hp, 215 lb-ft per Wikipedia; 307 cu in (5,031 cc) V8, 1973 only, 115 or 130 hp per Hagerty; 350 cu in (5,736 cc) V8, four-barrel, 155 hp for 1973 per Hagerty and 175 hp per Wikipedia (disputed); not offered on the C10 from 1981 through 1986; 1987 throttle-body injected version 210 hp at 4,000 rpm and 300 lb-ft at 2,800 rpm per GM; 454 cu in (7,440 cc) V8, 240 hp per Hagerty and The Autopian, 230 hp per Wikipedia (disputed); two-wheel-drive C trucks only and dropped below 8,501 lb GVWR for 1980; 305 cu in (4,998 cc) V8, added for 1977 on half-ton C trucks; 145 hp two-barrel per Hagerty, 160 hp four-barrel per Wikipedia; throttle-body injected for 1987; 350 cu in (5,736 cc) Oldsmobile LF9 diesel V8, 120 hp and 220 lb-ft, half-ton C trucks from 1978; end year disputed (1978 only, or through 1981); 379 cu in (6,211 cc) Detroit Diesel V8 from 1982, 130 hp at 3,600 rpm and 240 lb-ft at 2,000 rpm per GM's 1987 kit, 135 hp per Wikipedia and The Autopian; 262 cu in (4.3 liter) V6, 155 hp, base engine from 1985; throttle-body fuel injection for 1987
- Production notes: No source consulted gives a production total for the half-ton C10 square body, and the figures that circulate cannot all be true. Hagerty says Chevrolet sold 666,619 C/K trucks for the 1973 model year and notes that GMC figures were not available. Drivingline says more than a million examples were sold in the first year. J. Kelly Flory's reference book American Light Trucks and Utility Vehicles, 1967-1989, read as Google Books snippets, puts all 1973 model year Chevrolet light-truck production at 897,098, which covers El Camino, vans and the LUV as well as C/K pickups, so Drivingline's million can only be right if it counts GMC, Blazer and Suburban too. For 1978 Flory gives 1,233,712 Chevrolet light trucks of every type, while a classic.com listing page says 1,317,466 C/K trucks were sold that year, a figure larger than Chevrolet's entire light-truck output unless it includes GMC or counts calendar-year sales. Classic Decoder's over 75,000 by 1975 and High Flow Fuel's estimate of over 10 million across the run fit none of these. For 1987 Flory gives 1,072,530 Chevrolet light trucks of all types. No source breaks out the C10 alone, regular cab against crew cab, Fleetside against Stepside or two-wheel against four-wheel drive, so this page prints no total and no variant counts. Price is a similar gap: Flory gives a 1973 base price range of $2,107 to $4,102 for all Chevrolet light trucks and a Chevrolet average base price of $3,195, and an average of $10,728 for 1987, but there is no documented US list price for a specific C10 configuration in the sources consulted. Nothing here came from the GM archive or a registry; GM's own 1987 dealer kit was read for specifications only.

## Summary
The square body is Chevrolet's third-generation C/K pickup, sold in the US for model years 1973 through 1987 and carried on as heavier R/V trucks beside the GMT400 until 1991. Development began in 1968 and the brief was a truck that could double as a daily driver: more glass, a lower cab on a new frame, front disc brakes as standard. The half-ton C10 launched with a 250 cu in six and V8s up to the 454, took the Oldsmobile 350 diesel for 1978, was reskinned for 1981 with up to 300 lb taken out, got the 4.3-liter V6 for 1985 and throttle-body injection for 1987. Nobody publishes a C10-only production count, and the figures that circulate, from 666,619 Chevrolet C/K trucks for 1973 to an estimated 10 million overall, never state their scope. A reference book puts 1973 Chevrolet light-truck base prices at $2,107 to $4,102, but there is no documented US list price for a specific C10. As of September 2026 classic.com puts the average third-generation C10 sale at $23,924.

## Specifications
- power: Disputed by source: 1973 350 at 155 hp (Hagerty) or 175 hp (Wikipedia); 454 at 240 hp (Hagerty, The Autopian) or 230 hp (Wikipedia); 1987 injected 350 at 210 hp per GM
- diesel: Oldsmobile 350 diesel from 1978 (end year disputed); 6.2-liter Detroit Diesel from 1982
- engine: 250 and 292 cu in inline sixes, 307 (1973 only), 305, 350 and 454 cu in V8s, the 4.3-liter V6 from 1985, the Oldsmobile 350 diesel from 1978 and the 6.2-liter Detroit Diesel from 1982
- layout: Front-engine pickup; C series two-wheel drive and K series four-wheel drive, renamed R and V for 1987
- torque: 250 six 185 lb-ft; Olds diesel 220 lb-ft; 6.2 diesel 240 lb-ft; 1987 injected 350 300 lb-ft at 2,800 rpm per GM
- weight: No per-model curb weight retrieved; the 1981 redesign cut up to 300 lb depending on configuration per Hagerty
- chassis: Ladder frame new for 1973 with a lower cab, softer front springs, a new front anti-roll bar, standard front disc brakes and two-stage rear leaf springs; mid-cycle reskin for 1981
- emissions: Catalytic converters from 1975 below about 6,000 lb GVWR; standard below 8,500 lb from 1979 per Hagerty
- wheelbase: 117.5 in (2,985 mm) short bed and 131.5 in (3,340 mm) long bed per Hagerty and Wikipedia
- cab_styles: Two-door regular cab; four-door crew cab; Bonus Cab with the rear seat deleted
- end_of_run: Renamed R/V for 1987 and sold beside the GMT400; only the three-quarter ton remained by 1990; gone after 1991
- acceleration: Not stated in any source consulted; the 1973 Motor Trend test was readable only as snippets with no 0-60 figure
- fuel_economy: The Autopian quotes 20 mpg city and 28 mpg highway for the diesel C10 against 12 and 16 for the big block; period figures, not current EPA ratings
- period_press: Motor Trend's 1973 pickup test found the Cheyenne's 350 labored under its emissions equipment
- transmission: Three- and four-speed manuals and three-speed Turbo Hydra-Matic at launch; four-speed 700R4 overdrive automatic from 1982; EPA lists 3- and 4-speed manuals and 3- and 4-speed automatics for the 1986 C10
- us_list_price: No documented US list price for a specific C10; 1973 Chevrolet light-truck base prices ran $2,107 to $4,102 per Flory
- fuel_injection: Throttle-body injection on the 4.3, 5.0, 5.7 and 7.4-liter gasoline engines for 1987

## Notable variants
- Custom Deluxe, base trim: The base trim from 1975. Most unrestored survivors are Custom Deluxes, and they are also the trucks most often lowered and re-engined, like the 1985 example that sold on Hagerty Marketplace in September 2026 on 20-inch wheels.
- Cheyenne and Cheyenne Super, 1973-1982: Cheyenne Super (code YE9) was the 1973 top trim with extra wood grain and optional buckets; Cheyenne became one of four trims from 1975 and was deleted for 1982. The lowest classic.com sale for the generation, $1,300 in June 2026, was a 1973 Cheyenne/Super long bed, which shows how wide the condition range is.
- Silverado and Scottsdale: The upper and middle trims from 1975 onward. Square headlamps were Silverado-only for 1980, so a round-headlamp 1980 truck is the common one.
- BIG 10, 1975 on: A half-ton built to 6,050 lb GVWR, just over the line where catalytic converters were required, so it ran on cheaper leaded fuel. The badge on the trailing edge of the bed is the tell.
- Half-ton C10 with the Oldsmobile diesel: Introduced for 1978 at 120 hp and 220 lb-ft. Sources disagree on whether it was a 1978-only C10 option or ran through 1981, and Hagerty notes that a diesel truck not converted to a gasoline V8 is now a rare find.
- 1980 egg-crate grille: A parts supplier's identification guide says the 1980 egg-crate grille was made for one year only, which is the quickest way to place a 1980 truck from across a parking lot.
- 1987 R10 with throttle-body injection: The last year, renamed R/V, and the only year with fuel injection on the gasoline engines. GM's 1987 kit rates the light-duty injected 350 at 210 hp, the highest small-block rating in the sources consulted.

## History

### Why the square body exists

Development of the third-generation C/K began in 1968, and Wikipedia notes that components were tested in computer simulation before the first prototypes were built. Hagerty adds that the body spent time in the wind tunnel, which is why the corners are rounded and the side glass is curved on a truck everyone calls square. The truck it replaced was the Action Line, covered on its own page. The job was not more payload. Drivingline says Chevrolet and GMC were ready to push toward comfortable, capable trucks that could double as daily drivers, and High Flow Fuel lists larger glass, curved side windows and a roomier cab. The new frame let the cab sit lower, the front springs were softened, a front anti-roll bar was added and front disc brakes became standard.

### 1973: what was new

Five engines were offered at launch: 250 and 292 cu in sixes and 307, 350 and 454 cu in V8s. The 307 lasted one year; Wikipedia says it was offered only for 1973, Hagerty says it was dropped for 1974, and RM Sotheby's sold a documented 1973 C10 with a 307 and its factory build sheet at Auburn in 2012. Short beds rode a 117.5 in wheelbase and long beds 131.5 in. A four-door crew cab arrived for one-ton trucks, along with the dual-rear-wheel Big Dooley. The fuel tank moved out of the cab to a sidesaddle position outside the frame rail, a decision that would return twenty years later. Motor Trend's 1973 pickup test found the Cheyenne's 350 labored and judged that the 1973 cars handled their smog equipment better than the trucks did.

### 1974 through 1980

Catalytic converters arrived for 1975 on trucks under about 6,000 lb GVWR, and Chevrolet answered with the BIG 10, a half-ton rated at 6,050 lb that sat just over the line and ran on leaded fuel. The 400 V8 joined the K trucks the same year. For 1977 the grille was revised again and a 305 V8 arrived for half-ton C trucks. The 1978 Oldsmobile 350 diesel, at 120 hp and 220 lb-ft, made GM the first major American maker to sell a light-duty diesel pickup. The 454 was dropped from trucks under 8,501 lb GVWR for 1980, the year of the one-off egg-crate grille.

### The diesel and the 1981 refresh

The diesel shared its head bolts and bolt pattern with the gasoline engine, and The Autopian and Wikipedia describe stretched bolts, blown head gaskets and, per The Autopian, a period when GM could not sell it in California. Sources disagree on whether the half-ton kept it after 1978. For 1981 the trucks got new sheet metal, a new dashboard and up to 300 lb less weight, the fuel tank moved to the driver's side, and the 350 disappeared from the C10 order sheet until 1987.

### 1982 through 1987, and after

For 1982 the 379 cu in (6.2 liter) Detroit Diesel replaced the Oldsmobile engine and the four-speed 700R4 overdrive automatic arrived; the Cheyenne trim was dropped. The 4.3-liter V6 replaced the 250 six for 1985. For 1987 GM renamed the line R/V and fitted throttle-body injection to the gasoline engines, and its dealer kit rates the injected light-duty 350 at 210 hp. Drivingline says the R/V trucks were sold alongside the GMT400; by 1990 only the three-quarter ton remained, and after 1991 the square bodies were gone. Those later trucks are a note here, not part of this page.

## What to look for

The first question on a square body is what year it is, because the years look alike and the drivetrains changed. One parts-supplier guide gives a grille key: a recessed egg-crate grille for 1973-1974, a bolder flush grille from 1975, more horizontal lines for 1977, a one-year egg-crate for 1980, a new front end from 1981, another grille for 1983 and a further change for 1985. Square headlamps on a 1980 truck mean Silverado; round ones were the common setup. The engine should match the year. The 307 was a 1973-only engine, the 454 left trucks under 8,501 lb GVWR after 1979, and the 350 was not offered on the C10 from 1981 through 1986, which the EPA's 1986 listings also show, so a 350 in a 1981-1986 C10 is a later swap unless the paperwork says otherwise. Swaps are common: the one-family 1978 truck sold on Hagerty Marketplace in July 2026 carried a crate 350 installed in 2000. A diesel truck still running its Oldsmobile engine is rare. A BIG 10 badge on a 1975 or later half-ton means a 6,050 lb GVWR truck built to sit above the catalytic converter line. Two recalls are worth matching to the VIN: the 1976-1977 accelerator pedal rod that could cut into the floor mat, and the 1982 campaign for brake drum balance weights contacting aluminum wheels. The sidesaddle tanks got plastic shields for 1984. On rust, no specialist survey was retrievable; owner comments describe early trucks rusting over the rear wheel wells, and the 1978 Hagerty truck showed rust-through on the tailgate.

## Common problems

The best-documented fault is the 1978 Oldsmobile 350 diesel. It kept the gasoline engine's head bolts and bolt pattern, and Hagerty, Wikipedia and The Autopian describe head bolt failures and blown head gaskets; GM also left out a water separator to save money, and The Autopian reports the engine could not be sold in California in 1979 and early 1980. The 6.2-liter Detroit Diesel that replaced it from 1982 is described by Hagerty as highly regarded. NHTSA's recall database, queried for each C10 model year, adds the factory-level record: 77V178000 (1976-1977) for an accelerator pedal rod that could catch in the mat and hold the throttle open, 77V171000 (1977) for trucks built with a standard front suspension where heavy-duty was specified, 81V148000 and 81V118000 (1981) for substandard brake fluid and an oversize spare wheel, 82V128000 and 83V045000 (1982) for brake drum weights loosening aluminum wheels and a differential pinion shaft locking screw, and 87V043000 (1985-1986) for wrong-size rear brake assemblies. The sidesaddle fuel tanks drew a staged Dateline NBC crash in 1992, lawsuits and a 1994 GM settlement with NHTSA of $51 million for safety programs; Wikipedia reports GM's investigators found the tested tanks had not ruptured. Rust is the gap: owner comments describe 1973-1975 trucks rusting over the rear wheel wells after one salted winter, but no specialist rust survey or repair-cost figure was retrievable, so none is given.

## Market notes

As of September 2026 classic.com lists the average price of a third-generation C10 at $23,924, with 98 trucks listed and a lowest recorded sale of $1,300 for a 1973 Cheyenne/Super long bed on June 13, 2026. A classic.com dealer listing for a 1978 Scottsdale short bed asked $33,100 in August 2026 and shows a comparable-sales range of $14,787 to $37,011; that is an asking price, not a sale. Two Hagerty Marketplace auctions show where ordinary trucks land: a one-family 1978 C10 with a replacement 350 crate engine, a 1990s repaint and rust-through on the tailgate sold for $9,898 in July 2026, and a lowered 1985 C10 Custom Deluxe with its 305 and 700R4 on 20-inch wheels sold for $15,783 in September 2026, the page showing a last bid of $14,750. SlashGear, undated in the text consulted, counts 1,326 square body sales over five years worth $34.5 million, an average near $26,000, and a record of $228,250 for a 1983 C10 Custom at Mecum in January 2023; its figures cover all square body trucks, and Mecum's premium is not separated from the hammer. For an older reference point, RM Sotheby's sold a documented 27,444-mile 1973 C10 with a 307 and its build sheet for $13,750 at Auburn in fall 2012. No Hagerty valuation or Bring a Trailer figure is quoted because those pages could not be retrieved.

## Value trajectory

As of September 2026 the average third-generation C10 on classic.com is $23,924, against a floor of $1,300 for a 1973 Cheyenne/Super long bed sold June 13, 2026. The ordinary middle shows in two 2026 Hagerty Marketplace results, $9,898 in July for a re-engined 1978 C10 and $15,783 in September for a modified 1985 Custom Deluxe. The top is thin: SlashGear's record is the $228,250 Mecum sale of a 1983 C10 Custom in January 2023, far above everything else cited here. The one older data point is RM Sotheby's 2012 sale of a documented, 27,444-mile 1973 C10 at $13,750, below today's classic.com average, but one lot is not a trend and the two figures describe different trucks. Against the 1973 Chevrolet light-truck base price range of $2,107 to $4,102 in Flory's reference book, current averages are several times the original sticker in nominal dollars, though no C10-specific list price was documented and no inflation-adjusted comparison is made. Nothing fetched breaks the spread out by trim, engine or originality.

## Sources

- [A History of the 1973-1987 Chevrolet Square Body Pickup, GM's Longest-Running Classic Truck](https://drivingline.com/articles/a-history-of-the-1973-1987-chevrolet-square-body-pickup-gms-longest-running-classic-truck) (Driving Line)
- [What Years Did Chevy Make Square Body Trucks (And How Much One's Worth Today)?](https://www.slashgear.com/1671379/chevy-square-body-trucks-years-made-cost-today) (SlashGear)
- [Chevrolet C/K (third generation)](https://en.wikipedia.org/wiki/Chevrolet_C/K_(third_generation)) (Wikipedia)
- [1978 Chevrolet C10 Scottsdale Short Bed Pickup](https://www.classic.com/veh/1978-chevrolet-c10-scottsdale-short-bed-pickup-ccu-pJQ7jKW/) (classic.com)
- [Chevrolet C/K 3rd Gen C10 market page](https://www.classic.com/m/chevrolet/ck/3rd-gen/c10) (classic.com)
- [What Is a Square Body Truck: The Complete History](https://www.classicdecoder.com/blog/what-is-a-square-body-truck-the-complete-history) (Classic Decoder)
- [NHTSA recalls by vehicle: 1985 Chevrolet C10](https://api.nhtsa.gov/recalls/recallsByVehicle?make=chevrolet&model=c10&modelYear=1985) (National Highway Traffic Safety Administration)
- [Square Body Chevy Identification Guide](https://www.cjponyparts.com/resources/square-body-chevy-identification-guide) (CJ Pony Parts)
- [Square Body Trucks: A Brief History](https://www.highflowfuel.com/blog/square-body-trucks-a-brief-history/) (High Flow Fuel)
- [1973-87 Chevrolet/GMC Truck buyers guide](https://www.hagerty.com/media/buying-and-selling/1973-1987-chevrolet-gmc-truck-buyers-guide/) (Hagerty)
- [Motor Trend, 1973 (pickup comparison test, page 125), Google Books snippet](https://www.google.com/books/feeds/volumes?max-results=20&q=%22Motor+Trend%22+1973+Cheyenne+%22350+cu.+in.+V-8+labored%22) (Motor Trend via Google Books)
- [American Light Trucks and Utility Vehicles, 1967-1989 (J. Kelly Flory Jr., McFarland, 2019), 1973 Chevrolet entry, Google Books snippet](https://www.google.com/books/feeds/volumes?max-results=20&q=%22Chevrolet%22+%22pickup%22+%22C10%22+%22base+price%22+1973) (McFarland via Google Books)
- [American Light Trucks and Utility Vehicles, 1967-1989 (Flory), 1973 Chevrolet production line, Google Books snippet](https://www.google.com/books/feeds/volumes?max-results=20&q=%221973+Chevrolet%22+%22Model+year+production%22) (McFarland via Google Books)
- [American Light Trucks and Utility Vehicles, 1967-1989 (Flory), 1978 Chevrolet production line, Google Books snippet](https://www.google.com/books/feeds/volumes?max-results=20&q=%221978+Chevrolet%22+%22Model+year+production%22) (McFarland via Google Books)
- [American Light Trucks and Utility Vehicles, 1967-1989 (Flory), 1987 Chevrolet entry, Google Books snippet](https://www.google.com/books/feeds/volumes?max-results=20&q=%22Chevrolet+average+base+price%22+1987) (McFarland via Google Books)
- [1987 Chevrolet Truck Vehicle Information Kit (R/V Pickups), February 1987](https://archive.org/download/1987-chevrolet-truck-vik/1987-Chevrolet-Truck%20VIK_djvu.txt) (General Motors Corporation (scan on archive.org))
- [fueleconomy.gov model options: 1986 Chevrolet C10 Pickup 2WD](https://www.fueleconomy.gov/ws/rest/vehicle/menu/options?year=1986&make=Chevrolet&model=C10%20Pickup%202WD) (US EPA / Department of Energy)
- [NHTSA recalls by vehicle: 1977 Chevrolet C10](https://api.nhtsa.gov/recalls/recallsByVehicle?make=chevrolet&model=c10&modelYear=1977) (National Highway Traffic Safety Administration)
- [NHTSA recalls by vehicle: 1981 Chevrolet C10](https://api.nhtsa.gov/recalls/recallsByVehicle?make=chevrolet&model=c10&modelYear=1981) (National Highway Traffic Safety Administration)
- [NHTSA recalls by vehicle: 1982 Chevrolet C10](https://api.nhtsa.gov/recalls/recallsByVehicle?make=chevrolet&model=c10&modelYear=1982) (National Highway Traffic Safety Administration)
- [1973 Chevrolet C10, Auburn Fall 2012, Lot 3054](https://rmsothebys.com/auctions/af12/lots/r419-1973-chevrolet-c10) (RM Sotheby's)
- [One-Family-Owned 1978 Chevrolet C10 Pickup](https://www.hagerty.com/marketplace/auction/1978-chevrolet-c10/c8a4c384-12e4-4f0f-9f18-b0bc332b6fa5) (Hagerty Marketplace)
- [1985 Chevrolet C10 Custom Deluxe](https://www.hagerty.com/marketplace/auction/1985-chevrolet-c10/afbe6e21-37d1-4e61-a940-df2c359cdfc5) (Hagerty Marketplace)
- [Let's Look Back At Chevy's First Diesel Pickup, An Engineering Disaster Based On A Gas V8](https://www.theautopian.com/lets-look-back-at-chevys-first-diesel-pickup-an-engineering-disaster-based-on-a-gas-v8/) (The Autopian)
- [Oldsmobile Diesel engine](https://en.wikipedia.org/wiki/Oldsmobile_Diesel_engine) (Wikipedia)
- [Legends Of Chevy Trucks Honors The 1973 C/K Square Body (reader comments)](https://gmauthority.com/blog/2020/10/legends-of-chevy-trucks-honors-the-1973-c-k-square-body/) (GM Authority)

Cite as: Fully Sorted, "Chevrolet C10 (Square body, third generation)", https://fullysorted.com/research/models/chevrolet/c10-square-body, updated 2026-10-01.