The C/K is the name for Chevrolet and GMC's full-size pickup truck line from 1960 until 1998. The first Chevrolet pickup truck appeared in 1924, though in-house designs did not appear until 1930. "C" trucks had two-wheel drive while "K" models had four-wheel drive. The C/K light-duty pickup truck was replaced with the GMC Sierra in 1988 and the Chevrolet Silverado in 1999; the Chevrolet Silverado HD and GMC Sierra HD heavy-duty pickup trucks followed in 2001.
|Also called||GMC C/K |
GMC Sierra Classic
GMC High Sierra
|Successor||Chevrolet Silverado/GMC Sierra|
|Class||Full-size pickup truck|
|Body style(s)||2-door regular cab |
3-door extended cab
4-door crew cab
|Layout||Front engine, rear-wheel drive / four-wheel drive|
|Also called||C10/K10 |
|Engine(s)||230 in³ (3.8 L) I6 |
327 in³ (5.4 L) V8
The 1960 model year introduced a new body style of light pick-up truck that featured many firsts. Most important of these were a drop-center ladder frame, allowing the cab to sit lower, and independent front suspension, giving an almost car-like ride in a truck. Also new for 1960 was a new designation system for trucks made by GM. Gone was the 3100, 3200, and 3600 designations for short 1/2, long 1/2 and 3/4-ton models. Instead, a new scheme would assign a 10, 20, or 30 for 1/2, 3/4, and 1-ton models. Since 1957, trucks were available from the factory as 4-wheel drive, and the new class scheme would make this known, a C (Conventional) in front of the series number would indicate 2-wheel rear drive, a K would denote 4-wheel drive. Actual badging on trucks still carried the series name system from the previous generation. The 10, 20, and 30 series (C or K) were badged as "Apache 10", etc., 40, 50, and 60 series trucks were badged as "Viking 40", and the largest 70, 80, and 90 series models were marked "Spartan 70" etc. in 1960, C/K trucks were available in smooth "Fleetside" or fendered "Stepside" versions. GMC called these "Wideside" and "Fenderside." Half-ton models were the C10 and K10 short-bed trucks, and C15 and K15 long-bed trucks. The 3/4-ton C20 and K20, as well as the one-ton C30, were also available. GMC did not use the "C" nomenclature, though their 4x4 versions had the "K" designation. The 1962 model used torsion bar front suspension, with trailing arm suspension rear. Trim lines were base and "Custom." Engines included the base GMC 305 in³ V6 for the GMC version, 135 hp (101 kW) 236 in³ (3.9 L) and 150 hp (112 kW) 261 in³ (4.3 L) straight-6s, and a 283 in³ (4.6 L) V8 with 185 hp (119 kW).
A coil-spring front suspension came in 1963; along with a new base engine, a 140 hp (104 kW) 230 in³ (3.8 L) I6, and an optional 165 hp (123 kW) 292 in³ (4.8 L) I6. The cab was changed for 1964, with elimination of the "wraparound" windshield and a new front grille design, along with various interior changes. Air conditioning and a 220 hp (164 kW) 327 in³ (5.4 L) V8 came in 1965. A new base engine finished the model in 1966 with a 155 hp (116 kW) 250 in³ (4.1 L) I6.
|Assembly||Atlanta, GA |
Kansas City, MO
St. Louis, MO
|Engine(s)||250 cu in (4.1 L) I6 |
402 cu in (6.6 L) V8
|Transmission(s)||3 speed manual |
2-speed Powerglide automatic
3-speed THM-350 automatic
3-speed THM-400 automatic
|Wheelbase||115" Shortbox |
1967 A new, more modern look came in 1967. It was with this revision of the C/K truck that General Motors began to market trucks as general transportation rather than as work vehicles and nothing else. The majority of 10 and 20 series Chevrolet trucks from 1967 to 1972 were shipped with a coil spring trailing arm rear suspension, which greatly improved the ride over traditional leaf springs. However, leaf spring rear suspension was available on all trucks, and standard on 30 series trucks. GMC models came standard with leaf springs with coils springs optional; all four-wheel drive models (Chevrolet & GMC) had leaf springs on both axles. The standard drivetrain came with a 3 speed manual transmission and one of two engines; the 250 in³ straight-6 or the 283 cu in (4.6 L) V8. The optional transmissions were the 4 speed manual, the Powerglide and the Turbo-Hydromatic. The 292 in³ straight-6 and the 327 in³ V8 were the optional engines. The 1/2 ton trucks came with a (6 x 5.5") bolt pattern. However the 3/4 and 1 ton trucks came with (8 x 6") bolt pattern.
1968 In 1968, the 283 cu in (4.6 L) V8 was replaced with a 307 cu in (5 L) and a 310 hp (231 kW), 396 cu in (6.5 L) V8 was offered for the first time. The most visible change in differentiating a 1968 from a 1967 was the addition of side-marker reflectors on all fenders. Also, the small rear window cab was no longer available. The GMC grille was revised, with the letters "GMC" no longer embossed in the horizontal crossbar. Another note for restoration is that the front of the 1967-68 hood was slightly less (approx. 65 degree angle)sloped and without 67-68 fenders, the hood will not fit 1969-1972 models. Another addition was the Custom Comfort and Convenience interior package that fell between the Standard cab and CST cab options. 1968 was also the year that Chevrolet celebrated 50 years of truck manufacturing. Also in 1968 the 3/4 ton Longhorn model was added to the lineup. The Longhorns were designed with a strong 8 1/2 foot box that could hold a big slide-in truck camper.
1969 1969 saw a new V8 engine: a 255 hp (190 kW), 350 cu in (5.7 L). Along with the new engines came a new grille design for Chevrolet trucks and a more upright hood for both Chevrolet and GMC trucks. A utility variant known as the K5 Blazer was also introduced with a shorter wheelbase of 104 inches (2,642 mm). The GMC version, known as the Jimmy, was introduced the same year. Some internal cab changes were also made, most notably the switch from a hand-operated parking brake to a foot pedal, and a more modern looking 2-spoke steering wheel with plastic horn button replaced the previous year's 3-spoke wheel with chrome horn button. Also new this year was upper and lower side moldings, which added another two-tone paint option. These were standard on CST trucks, and optional in any other trim level.
1970 The only noticeable change for 1970 was a minor update to the Chevrolet grille. At first glance, the 1969 and 1970 grille appear identical. However, 1970's plastic inserts actually have highlights that break the appearance into 6 separate sections.
1971 Several changes occurred in 1971. First came another new grille design (the "egg crate") for Chevrolet trucks and black paint over portions of the GMC grille. Second, an additional trim package was introduced: the Cheyenne. On GMC models, this was referred to as the Sierra. These packages consisted mostly of comfort features — nicer interiors, more padding and insulation, carpet, chrome trim, and upper and lower side molding and tailgate trim. 1971 was the first year for AM/FM radios factory installed. Finally, the front brakes on all light-duty trucks were switched from drum brakes to disc brakes, resulting in much less brake fade under heavy use. While many prior C/K half-ton trucks had used a six-lug bolt pattern (6 x 5.5") for the wheels, two-wheel-drive models switched to a five-lug pattern (5 x 5" bolt circle) common to Buick, Oldsmobile, Pontiac, and Cadillac passenger cars. The 1/2 ton 4 x 4 retained the 6 lug bolt pattern. This bolt pattern would remain the standard through the end of the C/K series (along with the Chevrolet/GMC vans). Also, Chevrolet changed the 396 V8 emblem designation to 400 V8. The change was only cosmetic.
1972 1972 models were virtually identical to 1971 models with the only change being that the rear view mirror was glued to the windshield instead of being bolted to top of the cab, and metal or plastic flat door panels were no longer available; all trim levels had a more sculpted molded plastic door panel with integral armrests and wood grain inserts on Cheyenne and Sierra trim levels.
|283 in³ |
|307 in³ |
|305 in³||307 in³ |
|307 in³ |
|307 in³ |
|307 in³ |
|Years||2WD ½-ton||4WD ½-ton||¾ & 1-Ton|
|1967-70||6 x 5.5"||6 x 5.5"||8 x 6.5"|
|1971-72||5 x 5"||6 x 5.5"||8 x 6.5"|
In order, the new trim lines for 1967-1972 Chevrolet trucks were:
- C/10 - Base Model
- Custom/10 - 'Mid Level'
- CST/10 - 'Top of the Line' (CST=Custom Sport Truck)
- Custom/10 - Base Model
- CST/10 - 'Mid Level'
- Cheyenne/10 - 'Top of the line'
Late 1971, 1972:
- CST/10 - Base Model
- Cheyenne/10 - 'Mid Level'
- Cheyenne Super - 'Top of the Line'
- Cheyenne Highlander - Special 'Above top of line' package
A 10, 20, or 30 on the emblem indicates 1/2, 3/4, or 1 ton trucks.
GMC models form 1967 to 1970 used the same trim levels as the Chevrolets, except that the GMC trim levels were 1500, Custom 1500, and Super Custom 1500. Starting in 1971 this changed to:
- Custom 1500 - Base
- Super Custom 1500 - Mid
- Sierra 1500 - Top
And for late '71 and 1972:
- Super Custom 1500 - Base
- Sierra 1500 - Mid
- Sierra Grande 1500 - Top
- Sierra Highlander 1500 - Special extra top package.
On the GMC trucks 1500, 2500, and 3500 designations were used to indicate 1/2, 3/4, and 1-ton trucks.
In both series, the 'Highlander package' included special color-coordinated houndstooth cloth inserts and additional trim colors and insulation.
|Also called||Chevrolet Silverado |
|Production||1973–1987 (for 2-doors & 2-door cabs), 1973-1991 (for 4-door cabs)|
|Assembly||Atlanta, GA |
Kansas City, MO
St. Louis, MO
|Engine(s)||250 cu in (4.1 L) I6 |
Detroit Diesel 6.2 L V8
|Transmission(s)||3-speed THM-350 automatic |
|Wheelbase||117.5 in (2985 mm) |
131.5 in (3340 mm)
164.5 in (4178 mm)
- Fuel tanks are removed from the cab and fuel capacity is greatly increased with optional dual tanks (possible capacity up to 40 US gallons)
- This series has a longer wheelbase — 117.5 in (2985 mm) for short-bed and 131.5 in (3340 mm) for long-bed.
- A crew cab is introduced on a super-long 164.5 in wheelbase and is available with two options:
- The Bonus Cab has no rear seat but boasts "lockable storage".
- The Crew Cab "3+3" with a rear seat has room for 6.
- An all wheel drive system is an option from 1973-1980 using the heavy cast iron NP203 transfer case.
- Part time 4 wheel drive using the NP205 transfer case is available throughout the 14 year run.
- Ammeter installed in gauge package.
- Engine options are
- 105 hp 250 cu in (4.1 L) I6
- 120 hp 292 cu in (4.8 L) I6
- 130 hp 307 cu in (5 L) (1973 only)
- 250 hp 350 cu in (5.7 L) V8
- 245 hp 454 cu in (7.4 L) V8
- Trim levels for Chevrolet and GMC are:
- Custom/Sierra — base model. Rubber floor mat, vinyl seats, no headliner, manual door locks/windows.
- Scottsdale/Sierra Grande — chrome trim, everything the previous trim level has
- Cheyenne/High Sierra — brushed aluminum interior accents, cloth seats, chrome trim, carpet, air conditioning, headliner, more sound deadening/insulation (inside door panels, in the headliner, etc.).
- Cheyenne Super/Sierra Classic — wood interior accents, everything the previous trim level has, more chrome (i.e. bumpers and mirrors), tilt wheel, power doors/windows, and optionally cruise control. The "Cowboy Cadillac."
- One new engine choice 185 hp 400 cu in (6.6 L) V8 (1975-80)
- GM introduces 2 new trim levels, Silverado that replaces Cheyenne Super and Custom Deluxe that replaces Custom.
- Custom Deluxe/Sierra — base model. Rubber floor mat, vinyl seats, no headliner, manual door locks/windows, painted bumpers.
- Scottsdale/Sierra Grande — wood interior accents, chrome trim, cloth seats, everything the previous trim level has
- Cheyenne/High Sierra — carpet, door pockets, chrome trim, air conditioning, headliner, more sound deadening/insulation (inside door panels, in the headliner, etc.).
- Silverado/Sierra Classic — everything the previous trim level has, more chrome (i.e. bumpers and mirrors), tilt wheel, power doors/windows, and optionally cruise control. The "Cowboy Cadillac."
- Voltage Gauge replaces ammeter in gauge package.
- Electric Oil pressure gauge replaces mechanical in gauge package.
- A 4 wheel drive full ton chassis is added to the lineup.
- 125 hp 350 cu in (5.7 L) Oldsmobile Diesel V8 added in 1978 and discontinued in 1981.
- Last year for 185 hp 400 cu in (6.6 L) V8 (1975-80)
1981 body gets a facelift. Some options are removed or added.
- Gauge cluster font changes.
- Silverado/Sierra Classic — Wood interior accents changed to brushed aluminum.
- Halogen headlights made standard
- Revised side body trim
- A flatter grille and shorter hood changes the front end look
- 4Wheel drive changes:
- Automatic locking front hubs are added to light duty applications.
- A lighter NP208 aluminum transfer case replaces the heavy cast iron NP205 and NP203 in light duty 4x4 applications.
- The NP205 is still used in heavy duty trucks but all wheel drive is discontinued.
- 151 hp 379 cu in (6.2 L) Detroit Diesel V8 added
- TH700-R4 4 Speed Automatic Overdrive transmission is introduced.
- The Vortec 4.3L 4-BBL V6 replaces both Inline 6 engines
- Hydraulic clutches are introduced.
- GM introduces TBI fuel injection.
- GM changes the C/K to R/V (this is found in the 5th VIN digit). R/V is used as a transitional designation that remains in use until 1991 for the remaining production Third Generation full ton 30/35 models, V30/35 regular cab dually, crewcab, and SUVs (Chevrolet K5 Blazer and Suburban). From 1988 on C/K is used for the fourth generation trucks "GMT400" design.
Sidesaddle Fuel Tanks
The Third Generation of Chevrolet's full size pickup-truck line featured what became, well after production ended, a controversial design change. The fuel tank was relocated from the cab to outboard sides of one or both frame rails beneath the cab floor extending under the leading edge of the bed, commonly referred to as sidesaddle. This enlarged fuel capacity from 16 up to 40 gallons depending on wheelbase and the number of tanks. This also removed the tank from the passenger compartment.
According to the now debunked 1993 report aired on Dateline this placement made the trucks capable of exploding when involved in a side impact accident. Fatality figures vary wildly. A study by Failure Analysis Associates found 155 fatalities in these GM trucks between 1973 and 1989 involving both side impact and fire. The Center for Auto Safety Ralph Nader's lobbying group, lists "over 1,800 fatalities" between 1973 & 2000 involving both side impact and fire. GM never issued a recall, as recommended by the NHTSA. In 1993 the bad publicity generated by the later debunked Dateline story spawned several class action lawsuits. As settlement GM offered owners $1000 coupons toward the purchase of a new truck with a trade-in of the old one. Even though the trucks met NHTSA 15 and 20mph side impact crash test standards in place at the time of manufacture GM eventually settled with the NHTSA in 1994 for the amount of $51 million to be used for safety programs. The Fourth Generation (1988-2001) was designed and produced well before the lawsuits with one fuel tank inside the frame rails.
Fort Wayne, Indiana
|Engine(s)||4.3 L V6 |
6.5 L diesel V8
|Transmission(s)||3-speed THM-400 automatic |
New Venture Gear 4500 NV4500 transmission manual
|Wheelbase||117.5 in (2985 mm) |
131.5 in (3340 mm)
141.5 in (3594 mm)
155.5 in (3950 mm)
|Length||194.5 in (4940 mm) |
213.1 in (5413 mm)
218.5 in (5550 mm)
237.4 in (6030 mm)
|Width||76.8 in (1951 mm) |
77.1 in (1958 mm)
|Height||73.2 in (1859 mm) |
72.6 in (1844 mm)
Introduced in April 1987 as 1988 models (known as the GMT400 platform), there were eight different versions of the C/K line for 1988: Fleetside Single Cab, Fleetside Extended Cab, Fleetside Crew Cab, and Stepside Single Cab, each in either 2WD (C) or 4WD (K) drivelines. All C/K models would ride on independent front suspension. Three trim levels were available: Cheyenne, Scottsdale, and Silverado. Engines were a 160 hp (119 kW) 4.3 L V6, a 175 hp (130 kW) 5.0 L V8, a 210 hp (157 kW) 5.7 L V8 and a 6.2 L diesel V8. A 230 hp (172 kW) 7.4 L V8 was available in the 3/4-ton and one-ton trucks. In 1989, a fleetside Sport package was available with matching body color bumpers and grille, chrome wheels, and fog lights. A Z71 off-road package was also available with skid plates and Bilstein shocks. The Work Truck (W/T) was also introduced in 1990, which featured a single cab long bed with Cheyenne trim and new grille with black bumpers. Also in 1990 the GMC 3500 EFI with a powerful 454 (7.4 L) was available. The 454 EFI produced 230 hp (172 kW) and 385 lb·ft (522 N·m). In 1991, the 4L80-E automatic transmission was available for the 3/4-ton and one-ton trucks. In 1992, the 4-speed manual transmission was dropped and the stepside trucks were available with extended cabs. The 6.5 L diesel V8 was also made available with a turbocharger. In 1993, the Sport package was made available for the stepside models, featuring body color bumpers, mirrors, and grille with cast aluminum wheels. The 700R4 transmission was replaced with the 4L60-E automatic in 1993 also. In 1994, the 6.2 L diesel V8 was dropped and the trucks received grille updates. In 1995, the trucks received an updated audio system and interior (including full instrumentation with tachometer standard). Four wheel ABS brakes were made standard in 1995 as well as driver's side airbag on 1/2 ton models. The Vortec V8s were introduced in 1996, with power boosts across the board for the gasoline engines, thanks to high-flow cylinder heads, new camshaft, roller valve lifters and a higher compression ratio. Speed sensitive steering was introduced on the trucks in 1997 along with a passenger side airbag. 1998 saw a revision to the steering wheel and airbag system and also the addition of the PASSLOCK II antitheft system.
This platform was one of two where the traditional small-block Chevrolet V8 was last used (the G-series van was the last platform using the small block until the end of the 2002 model year).
The GMT800 platform was introduced in 1999 although the GMT400 platform was produced until the 2000 model year in response to fleet sales. Although no longer produced in the U.S., GMT400s are currently produced in Brazil powered with a Chevrolet inline six.
In 1990, Chevrolet introduced a high performance variant of the GMT400 under the Super Sport emblem called the SS'454 '. It was available in only regular cab short box half-ton 2-wheel drive specification in Onyx Black. The ss 454 was powered by a 454 cu in (7.4 L) V8 producing 230 hp (172 kW) and 385 lb·ft (522 N·m). A 3-speed automatic transmission and 3.73 rear axle ratio added to the truck's performance. The suspension was also upgraded with 32 mm (1.3 in) Bilstein gas-filled shock absorbers, a 32 mm (1.3 in) front stabilizer bar, and 12.7:1 fast-ratio steering gear assembly.
Unique exterior features included a front air dam with fog lights, special rims, decals displaying "SS 454 " on the trunk sides, red trim emblems, and black painted grille, bumpers, and mirrors. The interior was also unique with a special plush Garnet Red cloth with black trim, high-back reclining sport bucket seats, and center console.
MSRP of the 1990 model was US$18,295 with a US$550 destination charge. 16,953 total units were sold over the 4 years the SS 454 was in production with 1990, the first year of production, selling 13,748 units alone. The SS 454 was discontinued after the 1993 model year.
In 1991, GM introduced (under the Chevrolet and GMC nameplates) a truck that bridged the gap between pickups and medium duty trucks, the C3500HD. The C3500HD was only offered as a commercial chassis cab. The C3500HD came with regular cab as the only cab option until 1996, when the crew cab was also offered, it is not clear if the crew cab could only be ordered for fleets only, or if all consumers could order it as well. The extended cab was never offered on the C3500HD. All cabs came standard with upper marker/clearance lights. All but the most deluxe cab options were offered in the C3500HD, as well as all paint colors.
Engine offerings for the C3500HD included the 5.7L (until 1995, when it was dropped for the 96 model year) the 7.4L, and the 6.5L turbo diesel (the 6.2L diesel was never offered for the C3500HD, no diesel was offered for 1991, 1992 brought the 6.5L turbo diesel. The L65 code 6.5L turbo diesel was the only diesel offered in this truck). Transmission offerings were the 4L80E 4spd OD automatic, and the NV4500 5spd OD manual, these were the only two transmissions ever offered for the C3500HD. The common drive axle used on the C3500HD was the Dana 80, a full floating axle with an 11 inch ring gear. There have also been reports of Corporate 14 Bolt (a full floating axle with 10.5 inch ring gear) axles with upgraded axle tubes and hubs being installed. The front axle was a solid I-beam drop axle, similar to the axles of medium and heavy duty trucks. The GVWR of these trucks was 15,000 pounds. Both axles were suspended by leaf springs, and both axles had disc brakes. The wheelbases available were: 135.5", 159.5", and 183.5". The frames on these trucks were similar in design to the C3500 cab and chassis, but were heavily upgraded. the front and middle sections of the frame were hydroformed for strength and tight wheel cut, while from the back of the cab to the end of the truck, the frame was two parallel channels spaced at 34" for easy upfit.
While all other C/K pickup models were dropped by 2000, the C3500HD was produced until 2002 due to demand. In the brochures it is referred to as Sierra Classic/Silverado Classic. the only notable change was the replacement of the 7.4L Vortec Big Block with the 8.1L Vortec Big Block. otherwise, the 6.5L diesel was the only other engine, and the 4L80E and NV4500 were the transmission choices.
A variant of the C/K family was introduced in Brazil during the 1960s. These used the instrument cluster from the 1960-66 US Chevrolet C/K series although the exterior sheet metal layout is exclusive to Brazil. The models built included a light truck, named C-10, and a SUV named Veraneio (initially known simply as Chevrolet C-14/16), introduced in 1964. They were initially powered with a Chevrolet inline six based on the pre-1962 "Stovebolt" engines. In later years a four-cylinder diesel (Perkins Q20B) was also offered labeled as D-10 (light truck only). An alcohol-powered version of the pickup was offered beginning in the 1980s, dubbed the A-10.
After 1985, a redesigned pickup similar to the U.S. C/K series (1973-87 vintage) was introduced as the C-20, powered with the GM inline six of the U.S. Chevy II/Nova. Diesel and alcohol versions were also sold, labeled as D-20 and A-20 respectively (later models of the D-20 replaced the Perkins Q20B with a Maxion S4). The original version of the Veraneio was kept in production until 1988 (model year 1989), but it was eventually replaced with an updated version based on the C-20 family.
- 1979-1984 GM parts book LT Truck 52A Rev84.1 PG31
- 1979-1984 GM parts book LT Truck 52A Rev84.1 PG33
- chevytruckfanclub.com -Chevy Truck Fan Club of North America
- The scandal of punitive damages. Titled: "The Most Dangerous Vehicle On the Road", Wall Street Journal, February 9, 1993, By Walter Olson