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.
4x4 front suspension
A drastic difference between the 3rd generation and 4 generation GM trucks was the suspension. 3rd Generation 4x4 trucks used solid front axles. The 4 generation GM trucks used independent front suspension (IFS).
In 1989, a half ton 2WD fleetside Sport appearance package was available with black and red bumper and body trim, and a black grille with red outlined Chevrolet emblem, chrome wheels with custom center caps, and fog lights. The 89 was a limited production run set to determine how well the "sport" package would be received by consumers in the years to follow. The Sport package was more of a trim and towing package edition as well as a few engine enhancements that weren't on available on other Chevrolet trucks of the time.
Also in '89, the 4x4 sport appearance package included black bumper and body trim, wheel flares, mirrors, sport grille, 16" cast aluminum wheels and special "4x4" badging on the box and "SPORT" badged on the tailgate. The box and tailgate decals were flanked by red outlined Chevy bowties. The sport package was only offered from 1989 until 1992 as some insurance companies began to express concerns with the idea of a high performance truck. RPO code was BYP. This model was only available with the standard cab and regular fleet-side box. Colors included white, black, and red. 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 1988 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 1995, 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 available for the step-side models, featuring body-colored bumpers, mirrors, and grille with cast aluminum wheels. The 700R4 transmission was replaced with the 4L60-E automatic in 1993 also. In 1996, the 6.2 L diesel V8 was dropped. 1994 saw new grills on both the Chevrolet and GMC trucks. In 1995, the trucks received an updated audio system and interior (including full instrumentation with tachometer standard). Four wheel ABS brakes were standard in 1995 as well as a driver's side airbag on the 1/2 ton models. The Vortec V8s were introduced in 1996, with power boosts across the board for the gasoline engines. The Vortec V8's made between 255 to 290 horsepower, 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 anti-theft system.
Engines:
EngineYearsPowerTorqueNotes4.3 L V61988–92160 hp (120 kW)235 lb·ft (319 N·m)4.3 L V61993–95165 hp (123 kW)235 lb·ft (319 N·m)4.3 L V61996–98200 hp (150 kW)260 lb·ft (350 N·m)5.0 L V81988–95170 hp (130 kW)270 lb·ft (370 N·m)5.0 L V81996–99230 hp (170 kW)290 lb·ft (390 N·m)5.7 L V81988–95210 hp (160 kW)300 lb·ft (410 N·m)5.7 L V81996250 hp (190 kW)330 lb·ft (450 N·m)5.7 L V81997–99255 hp (190 kW)330 lb·ft (450 N·m)6.2 L V8 Diesel1991130 hp (97 kW)240 lb·ft (330 N·m)6.2 L V8 Diesel1992–93143 hp (107 kW)257 lb·ft (348 N·m)6.5 L V8 Diesel1994–99180 hp (130 kW)360 lb·ft (490 N·m)7.4 L V81996-00290 hp (220 kW)440 lb·ft (600 N·m)RPO L297.4 L V81990230 hp (170 kW)385 lb·ft (522 N·m)454 SS Option7.4 L V81991-93255 hp (190 kW)405 lb·ft (549 N·m)454 SS Option
1996 GMC K1500 Sierra
Mid-cycle refreshes
This refresh occurred over several model years.
1994 C/K's received a new front fascia, federally-mandated CHMSL, many new exterior colors including a new two-tone option on the rocker panels, and new tire and wheel combinations.
1995 C/K's received a new interior that included a new steering wheel containing a drivers side airbag, a new dashboard containing a more central-mounted radio, dial operated HVAC system and an improved gauge cluster. New front door panels, and new seating were also included. The only interior bits not redesigned were the interior panels rear of the doors. Exterior changes this year included a secial two tone faded paint job, available in many different varities new gloss black folding exterior mirrors, and the door handles were changed from a smooth gloss black finish to a textured, satin finish.
In 1996, a passenger side mounted 3rd door was optional on extended cab models. A new range of engines were included. The "Vortec" engines meant HP increases across gasoline V6 and V8 smallblock engines.
1997 saw a passenger-side airbag on some models in order to comply with new federal regulations for light trucks. 2500 and 3500 models are exempt. This meant a slight dashboard redesign to incorporate these airbags. On models where passenger airbags weren't included, the space was occupied by a storage compartment.
1998 meant minor trim and badge updates as GM readied the end of the GMT-400 Platform. There was some overlap in 1999-2002 model years. In response to continued fleet sales the GMT400 trucks were produced as the Sierra Classic/Silverado Classic until the T400 ended production at the end of the 2002 model year. A Brazilian version of the GMT400 is currently produced in Brazil powered with a Chevrolet inline six.
The T400 and G-Van were the last two platforms to utilize the traditional small-block Chevrolet V8 in the 2002 model year.
The GMT800 platform was introduced in 1999 as the Silverado/Sierra.
454 SS
In 1990, Chevrolet introduced a high performance variant of the GMT400 under the Super Sport emblem called the 454SS. It was available only as a 2WD half-ton regular cab short box in Onyx Black only with a garnet red interior. The 454SS was powered by a 454 cu in (7.4 L) V8 producing 230 hp (172 kW) and 385 lb·ft (522 N·m).[53] A 3-speed automatic transmission (Turbo Hydra-Matic 400) 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 "454SS" on the bed 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.
For 1991, a four-speed electronic automatic transmission (known as the 4L80E), 25 more horsepower, and even higher torque (405 lbs/ft at 2400 rpm) were added to the 454SS. The rear-axle ratio was also lowered to 4.10:1 for extra jolt off the line. On the dash was a tachometer, oddly omitted from 1990 models.
The MSRP of the 1990 model was US$18,295 with a $550 destination charge. A total of 16,953 units were sold over the 4 years the 454SS was in production, with 1990, the first year of production, selling 13,748 units alone. The 454SS was discontinued after the 1993 model year.
In 1992-1993 other color options included Summit White and Victory Red, with multiple interior colour options. The rear quarter panel and tailgate decals also changed in 1992 to a more 'stylized' 'SS' and the Chevrolet sticker on the tailgate became much smaller and located on the corner area.
GMC 3500HD Cab and Chassis with Dump Body
In 1991 GM introduced a 15,000 pound GVWR truck C3500 HD under the Chevrolet and GMC nameplates that was replaced by the 4500. It was marketed as a truck to bridge the gap between light duty trucks "pickup trucks" and medium duty trucks. The C3500 HD was only offered as a standard chassis cab until 1996 when a crew chassis cab was also offered. It is not clear if the crew cab was for fleet orders only, or if anyone could order it. An extended cab was never offered on the C3500 HD, though several have been custom made by the registered owners. All paint colors and all but the most deluxe cab options were offered in the C3500 HD. Upper cab marker/clearance lights were not optional equipment on the C 3500HD. The two mirror options are the camper style and west coast style mirrors.
The common drive axle used on the C3500 HD was the Dana 80, an 85.8" wide full floating axle with an 11 inch ring gear fitted with 19.5" x 6.0 tires. The front axle was a solid I-beam drop axle, similar to the axles of medium and heavy duty trucks. Both front and rear leaf sprung axles had disc brakes.
Available wheelbases were; 135.5", 159.5", and 183.5". The C3500 HD frames are very different from the C/K3500 cab and chassis. The C/K3500 cab and chassis and C3500 HD rear frame rails are spaced at industry standard 34" for easy fitment of bodies but that is where the similarity ends. The HD frame is much heavier and exits straight out behind the high mounted cab necessitating the unmistakable HD filler panel between the bumper and grille. The front fenders were also equipped with the same flares used on 4x4 models of the lighter trucks to cover the increased track width and larger tires.
Two transmissions were offered in the C3500 HD; the 4L80E 4spd OD automatic, and the NV4500 5spd manual.
GM never offered a four wheel drive counterpart of the C3500 HD, so there was no K3500 HD. Several aftermarket conversion companies offered a 4x4 version with either a Dana 60 or Dana 70 front axle. At least one company, Monroe Truck, was offered by GM dealers as a ship-through 4WD upfit using the RPO code VCB. Tulsa is another company that did 4x4 conversions for utility companies. Quigley conversions were mostly for fire/ambulance applications.
Engines 1991–2000
Engine offerings for the C3500 HD included three gasoline engines; from 1991-1995 5.7L 350 Small Block and 7.4L GEN V Big Block. In 1996 both the 5.7 and GEN V 7.4 were replaced by the new Gen VI 7.4L Vortec Big Block. The RPOL65 6.5L Turbo Diesel debuted in the C3500 HD in 1992, the year of the engine's release. The 6.5 was the only diesel engine offered for the entire production run of the T400 C3500 HD. No diesel was available for 1991, the first C3500 HD production year.
Engines 2001–2002
While all other C/K pickup models were dropped by 2000, the C3500 HD was produced until 2002 due to fleet demand. In the brochures it is referred to as Sierra Classic/Silverado Classic. There were two engine choices; The 8.1L Vortec Big Block replaced the Gen VI 7.4L Vortec Big Block and the venerable 6.5L Turbo Diesel.
4x4 front suspension
A drastic difference between the 3rd generation and 4 generation GM trucks was the suspension. 3rd Generation 4x4 trucks used solid front axles. The 4 generation GM trucks used independent front suspension (IFS).
In 1989, a half ton 2WD fleetside Sport appearance package was available with black and red bumper and body trim, and a black grille with red outlined Chevrolet emblem, chrome wheels with custom center caps, and fog lights. The 89 was a limited production run set to determine how well the "sport" package would be received by consumers in the years to follow. The Sport package was more of a trim and towing package edition as well as a few engine enhancements that weren't on available on other Chevrolet trucks of the time.
Also in '89, the 4x4 sport appearance package included black bumper and body trim, wheel flares, mirrors, sport grille, 16" cast aluminum wheels and special "4x4" badging on the box and "SPORT" badged on the tailgate. The box and tailgate decals were flanked by red outlined Chevy bowties. The sport package was only offered from 1989 until 1992 as some insurance companies began to express concerns with the idea of a high performance truck. RPO code was BYP. This model was only available with the standard cab and regular fleet-side box. Colors included white, black, and red. 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 1988 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 1995, 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 available for the step-side models, featuring body-colored bumpers, mirrors, and grille with cast aluminum wheels. The 700R4 transmission was replaced with the 4L60-E automatic in 1993 also. In 1996, the 6.2 L diesel V8 was dropped. 1994 saw new grills on both the Chevrolet and GMC trucks. In 1995, the trucks received an updated audio system and interior (including full instrumentation with tachometer standard). Four wheel ABS brakes were standard in 1995 as well as a driver's side airbag on the 1/2 ton models. The Vortec V8s were introduced in 1996, with power boosts across the board for the gasoline engines. The Vortec V8's made between 255 to 290 horsepower, 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 anti-theft system.
Engines:
EngineYearsPowerTorqueNotes4.3 L V61988–92160 hp (120 kW)235 lb·ft (319 N·m)4.3 L V61993–95165 hp (123 kW)235 lb·ft (319 N·m)4.3 L V61996–98200 hp (150 kW)260 lb·ft (350 N·m)5.0 L V81988–95170 hp (130 kW)270 lb·ft (370 N·m)5.0 L V81996–99230 hp (170 kW)290 lb·ft (390 N·m)5.7 L V81988–95210 hp (160 kW)300 lb·ft (410 N·m)5.7 L V81996250 hp (190 kW)330 lb·ft (450 N·m)5.7 L V81997–99255 hp (190 kW)330 lb·ft (450 N·m)6.2 L V8 Diesel1991130 hp (97 kW)240 lb·ft (330 N·m)6.2 L V8 Diesel1992–93143 hp (107 kW)257 lb·ft (348 N·m)6.5 L V8 Diesel1994–99180 hp (130 kW)360 lb·ft (490 N·m)7.4 L V81996-00290 hp (220 kW)440 lb·ft (600 N·m)RPO L297.4 L V81990230 hp (170 kW)385 lb·ft (522 N·m)454 SS Option7.4 L V81991-93255 hp (190 kW)405 lb·ft (549 N·m)454 SS Option


1996 GMC K1500 Sierra
Mid-cycle refreshes
This refresh occurred over several model years.
1994 C/K's received a new front fascia, federally-mandated CHMSL, many new exterior colors including a new two-tone option on the rocker panels, and new tire and wheel combinations.
1995 C/K's received a new interior that included a new steering wheel containing a drivers side airbag, a new dashboard containing a more central-mounted radio, dial operated HVAC system and an improved gauge cluster. New front door panels, and new seating were also included. The only interior bits not redesigned were the interior panels rear of the doors. Exterior changes this year included a secial two tone faded paint job, available in many different varities new gloss black folding exterior mirrors, and the door handles were changed from a smooth gloss black finish to a textured, satin finish.
In 1996, a passenger side mounted 3rd door was optional on extended cab models. A new range of engines were included. The "Vortec" engines meant HP increases across gasoline V6 and V8 smallblock engines.
1997 saw a passenger-side airbag on some models in order to comply with new federal regulations for light trucks. 2500 and 3500 models are exempt. This meant a slight dashboard redesign to incorporate these airbags. On models where passenger airbags weren't included, the space was occupied by a storage compartment.
1998 meant minor trim and badge updates as GM readied the end of the GMT-400 Platform. There was some overlap in 1999-2002 model years. In response to continued fleet sales the GMT400 trucks were produced as the Sierra Classic/Silverado Classic until the T400 ended production at the end of the 2002 model year. A Brazilian version of the GMT400 is currently produced in Brazil powered with a Chevrolet inline six.
The T400 and G-Van were the last two platforms to utilize the traditional small-block Chevrolet V8 in the 2002 model year.
The GMT800 platform was introduced in 1999 as the Silverado/Sierra.
454 SS
In 1990, Chevrolet introduced a high performance variant of the GMT400 under the Super Sport emblem called the 454SS. It was available only as a 2WD half-ton regular cab short box in Onyx Black only with a garnet red interior. The 454SS was powered by a 454 cu in (7.4 L) V8 producing 230 hp (172 kW) and 385 lb·ft (522 N·m).[53] A 3-speed automatic transmission (Turbo Hydra-Matic 400) 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 "454SS" on the bed 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.
For 1991, a four-speed electronic automatic transmission (known as the 4L80E), 25 more horsepower, and even higher torque (405 lbs/ft at 2400 rpm) were added to the 454SS. The rear-axle ratio was also lowered to 4.10:1 for extra jolt off the line. On the dash was a tachometer, oddly omitted from 1990 models.
The MSRP of the 1990 model was US$18,295 with a $550 destination charge. A total of 16,953 units were sold over the 4 years the 454SS was in production, with 1990, the first year of production, selling 13,748 units alone. The 454SS was discontinued after the 1993 model year.
In 1992-1993 other color options included Summit White and Victory Red, with multiple interior colour options. The rear quarter panel and tailgate decals also changed in 1992 to a more 'stylized' 'SS' and the Chevrolet sticker on the tailgate became much smaller and located on the corner area.
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Chevrolet 454SS
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1988–1989 Chevrolet C/K 1500 regular cab
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1988–1993 Chevrolet C/K conversion
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c. 1995–2000 K-Series brush truck near Tallahassee, Florida
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1988–1989 Chevrolet C/K regular cab
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1995-2000 Chevrolet C/K regular cab
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GMC C/K Sierra regular cab
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Chevrolet K2500 6.5 TurboDiesel with NV4500 Transmission
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Chevy K3500 Crew Cab "Dually"

GMC 3500HD Cab and Chassis with Dump Body
In 1991 GM introduced a 15,000 pound GVWR truck C3500 HD under the Chevrolet and GMC nameplates that was replaced by the 4500. It was marketed as a truck to bridge the gap between light duty trucks "pickup trucks" and medium duty trucks. The C3500 HD was only offered as a standard chassis cab until 1996 when a crew chassis cab was also offered. It is not clear if the crew cab was for fleet orders only, or if anyone could order it. An extended cab was never offered on the C3500 HD, though several have been custom made by the registered owners. All paint colors and all but the most deluxe cab options were offered in the C3500 HD. Upper cab marker/clearance lights were not optional equipment on the C 3500HD. The two mirror options are the camper style and west coast style mirrors.
The common drive axle used on the C3500 HD was the Dana 80, an 85.8" wide full floating axle with an 11 inch ring gear fitted with 19.5" x 6.0 tires. The front axle was a solid I-beam drop axle, similar to the axles of medium and heavy duty trucks. Both front and rear leaf sprung axles had disc brakes.
Available wheelbases were; 135.5", 159.5", and 183.5". The C3500 HD frames are very different from the C/K3500 cab and chassis. The C/K3500 cab and chassis and C3500 HD rear frame rails are spaced at industry standard 34" for easy fitment of bodies but that is where the similarity ends. The HD frame is much heavier and exits straight out behind the high mounted cab necessitating the unmistakable HD filler panel between the bumper and grille. The front fenders were also equipped with the same flares used on 4x4 models of the lighter trucks to cover the increased track width and larger tires.
Two transmissions were offered in the C3500 HD; the 4L80E 4spd OD automatic, and the NV4500 5spd manual.
GM never offered a four wheel drive counterpart of the C3500 HD, so there was no K3500 HD. Several aftermarket conversion companies offered a 4x4 version with either a Dana 60 or Dana 70 front axle. At least one company, Monroe Truck, was offered by GM dealers as a ship-through 4WD upfit using the RPO code VCB. Tulsa is another company that did 4x4 conversions for utility companies. Quigley conversions were mostly for fire/ambulance applications.
Engines 1991–2000
Engine offerings for the C3500 HD included three gasoline engines; from 1991-1995 5.7L 350 Small Block and 7.4L GEN V Big Block. In 1996 both the 5.7 and GEN V 7.4 were replaced by the new Gen VI 7.4L Vortec Big Block. The RPOL65 6.5L Turbo Diesel debuted in the C3500 HD in 1992, the year of the engine's release. The 6.5 was the only diesel engine offered for the entire production run of the T400 C3500 HD. No diesel was available for 1991, the first C3500 HD production year.
Engines 2001–2002
While all other C/K pickup models were dropped by 2000, the C3500 HD was produced until 2002 due to fleet demand. In the brochures it is referred to as Sierra Classic/Silverado Classic. There were two engine choices; The 8.1L Vortec Big Block replaced the Gen VI 7.4L Vortec Big Block and the venerable 6.5L Turbo Diesel.