General Motors 2500 · ¾-Ton
1989 · Chevrolet Chevrolet C/K 2500
Engine: GM 6.2L Detroit Diesel V8
143 hp · 257 lb-ft
2WD / 4WD · Transmission unknown
GM's 1989 kit rates the 6.2L LL4 (8501-10,000 lb GVWR) at 143 hp @ 3600 rpm and 257 lb-ft @ 2000 rpm. Lighter C/K trucks up to 8500 lb GVWR used the LH6, rated 126 hp @ 3600 / 240 lb-ft @ 2000 with the manual and 140 hp @ 3600 / 247 lb-ft @ 2000 with the automatic. Ratings shown are the heavy-duty LL4 figure, the highest offered in this row; the GVWR split between LL4 and LH6 means a lighter C/K 2500 could carry the lower LH6 rating. 1989-1991 overlapped with the older R/V-series trucks (R/V 2500/3500), which are not listed as separate rows. C = 2WD, K = 4WD. Transmission pairing and diesel availability by weight class unverified. These GM figures supersede the third-party numbers previously used here (150 hp / 265 lb-ft applied across 1989-1993, plus conflicting 130/240, 143/257 and 165/285 claims from ChevyTrucks.org, DieselHub and Wikipedia), which did not agree with each other or with GM's own year-by-year ratings.
1989 · GMC GMC Sierra C/K 2500
Engine: GM 6.2L Detroit Diesel V8
143 hp · 257 lb-ft
2WD / 4WD · Transmission unknown
GM's 1989 kit rates the 6.2L LL4 (8501-10,000 lb GVWR) at 143 hp @ 3600 rpm and 257 lb-ft @ 2000 rpm. Lighter C/K trucks up to 8500 lb GVWR used the LH6, rated 126 hp @ 3600 / 240 lb-ft @ 2000 with the manual and 140 hp @ 3600 / 247 lb-ft @ 2000 with the automatic. Ratings shown are the heavy-duty LL4 figure, the highest offered in this row; the GVWR split between LL4 and LH6 means a lighter C/K 2500 could carry the lower LH6 rating. 1989-1991 overlapped with the older R/V-series trucks (R/V 2500/3500), which are not listed as separate rows. C = 2WD, K = 4WD. Transmission pairing and diesel availability by weight class unverified. These GM figures supersede the third-party numbers previously used here (150 hp / 265 lb-ft applied across 1989-1993, plus conflicting 130/240, 143/257 and 165/285 claims from ChevyTrucks.org, DieselHub and Wikipedia), which did not agree with each other or with GM's own year-by-year ratings.
1990 · Chevrolet Chevrolet C/K 2500
Engine: GM 6.2L Detroit Diesel V8
150 hp · 265 lb-ft
2WD / 4WD · Transmission unknown
GM's 1990 kit rates the 6.2L LL4 at 150 hp @ 3600 rpm and 265 lb-ft @ 2000 rpm, on the engine power curves. The LH6 curves show 135 hp @ 3600 / 240 lb-ft @ 2000 and 140 hp @ 3600 / 250 lb-ft @ 2000. Ratings shown are the heavy-duty LL4 figure, the highest offered in this row; the GVWR split between LL4 and LH6 means a lighter C/K 2500 could carry the lower LH6 rating. 1989-1991 overlapped with the older R/V-series trucks (R/V 2500/3500), which are not listed as separate rows. C = 2WD, K = 4WD. Transmission pairing and diesel availability by weight class unverified. These GM figures supersede the third-party numbers previously used here (150 hp / 265 lb-ft applied across 1989-1993, plus conflicting 130/240, 143/257 and 165/285 claims from ChevyTrucks.org, DieselHub and Wikipedia), which did not agree with each other or with GM's own year-by-year ratings.
1990 · GMC GMC Sierra C/K 2500
Engine: GM 6.2L Detroit Diesel V8
150 hp · 265 lb-ft
2WD / 4WD · Transmission unknown
GM's 1990 kit rates the 6.2L LL4 at 150 hp @ 3600 rpm and 265 lb-ft @ 2000 rpm, on the engine power curves. The LH6 curves show 135 hp @ 3600 / 240 lb-ft @ 2000 and 140 hp @ 3600 / 250 lb-ft @ 2000. Ratings shown are the heavy-duty LL4 figure, the highest offered in this row; the GVWR split between LL4 and LH6 means a lighter C/K 2500 could carry the lower LH6 rating. 1989-1991 overlapped with the older R/V-series trucks (R/V 2500/3500), which are not listed as separate rows. C = 2WD, K = 4WD. Transmission pairing and diesel availability by weight class unverified. These GM figures supersede the third-party numbers previously used here (150 hp / 265 lb-ft applied across 1989-1993, plus conflicting 130/240, 143/257 and 165/285 claims from ChevyTrucks.org, DieselHub and Wikipedia), which did not agree with each other or with GM's own year-by-year ratings.
1991 · Chevrolet Chevrolet C/K 2500
Engine: GM 6.2L Detroit Diesel V8
150 hp · 280 lb-ft
2WD / 4WD · Transmission unknown
GM's 1991 kit rates the 6.2L LL4 (8600-10,000 lb GVWR) at 150 hp @ 3500 rpm and 280 lb-ft @ 2000 rpm. The LH6 (below 8600 lb GVWR) is rated 140 hp @ 3600 / 255 lb-ft @ 1900. Ratings shown are the heavy-duty LL4 figure, the highest offered in this row; the GVWR split between LL4 and LH6 means a lighter C/K 2500 could carry the lower LH6 rating. 1989-1991 overlapped with the older R/V-series trucks (R/V 2500/3500), which are not listed as separate rows. C = 2WD, K = 4WD. Transmission pairing and diesel availability by weight class unverified. These GM figures supersede the third-party numbers previously used here (150 hp / 265 lb-ft applied across 1989-1993, plus conflicting 130/240, 143/257 and 165/285 claims from ChevyTrucks.org, DieselHub and Wikipedia), which did not agree with each other or with GM's own year-by-year ratings.
1991 · GMC GMC Sierra C/K 2500
Engine: GM 6.2L Detroit Diesel V8
150 hp · 280 lb-ft
2WD / 4WD · Transmission unknown
GM's 1991 kit rates the 6.2L LL4 (8600-10,000 lb GVWR) at 150 hp @ 3500 rpm and 280 lb-ft @ 2000 rpm. The LH6 (below 8600 lb GVWR) is rated 140 hp @ 3600 / 255 lb-ft @ 1900. Ratings shown are the heavy-duty LL4 figure, the highest offered in this row; the GVWR split between LL4 and LH6 means a lighter C/K 2500 could carry the lower LH6 rating. 1989-1991 overlapped with the older R/V-series trucks (R/V 2500/3500), which are not listed as separate rows. C = 2WD, K = 4WD. Transmission pairing and diesel availability by weight class unverified. These GM figures supersede the third-party numbers previously used here (150 hp / 265 lb-ft applied across 1989-1993, plus conflicting 130/240, 143/257 and 165/285 claims from ChevyTrucks.org, DieselHub and Wikipedia), which did not agree with each other or with GM's own year-by-year ratings.
1992 · Chevrolet Chevrolet C/K 2500
Engine: GM 6.2L Detroit Diesel V8
148 hp · 246 lb-ft
2WD / 4WD · Transmission unknown
GM's 1992 kit rates the 6.2L LL4 (8600-10,000 lb GVWR) at 148 hp @ 3600 rpm and 246 lb-ft @ 2000 rpm. The LH6 (8500 lb GVWR and below) is rated 140 hp @ 3600 / 255 lb-ft @ 1900. The turbocharged 6.5L (L65) joined the range this year. Ratings shown are the heavy-duty LL4 figure, the highest offered in this row; the GVWR split between LL4 and LH6 means a lighter C/K 2500 could carry the lower LH6 rating. 1989-1991 overlapped with the older R/V-series trucks (R/V 2500/3500), which are not listed as separate rows. C = 2WD, K = 4WD. Transmission pairing and diesel availability by weight class unverified. These GM figures supersede the third-party numbers previously used here (150 hp / 265 lb-ft applied across 1989-1993, plus conflicting 130/240, 143/257 and 165/285 claims from ChevyTrucks.org, DieselHub and Wikipedia), which did not agree with each other or with GM's own year-by-year ratings.
1992 · GMC GMC Sierra C/K 2500
Engine: GM 6.2L Detroit Diesel V8
148 hp · 246 lb-ft
2WD / 4WD · Transmission unknown
GM's 1992 kit rates the 6.2L LL4 (8600-10,000 lb GVWR) at 148 hp @ 3600 rpm and 246 lb-ft @ 2000 rpm. The LH6 (8500 lb GVWR and below) is rated 140 hp @ 3600 / 255 lb-ft @ 1900. The turbocharged 6.5L (L65) joined the range this year. Ratings shown are the heavy-duty LL4 figure, the highest offered in this row; the GVWR split between LL4 and LH6 means a lighter C/K 2500 could carry the lower LH6 rating. 1989-1991 overlapped with the older R/V-series trucks (R/V 2500/3500), which are not listed as separate rows. C = 2WD, K = 4WD. Transmission pairing and diesel availability by weight class unverified. These GM figures supersede the third-party numbers previously used here (150 hp / 265 lb-ft applied across 1989-1993, plus conflicting 130/240, 143/257 and 165/285 claims from ChevyTrucks.org, DieselHub and Wikipedia), which did not agree with each other or with GM's own year-by-year ratings.
1992 · Chevrolet Chevrolet C/K 2500
Engine: GM 6.5L Turbo Detroit Diesel V8
180 hp · 380 lb-ft
2WD / 4WD · 4L80-E automatic, NV4500 manual
GM's 1992 kit rates the turbocharged 6.5L (L65, 8600-12,000 lb GVWR) at 180 hp @ 3500 rpm and 380 lb-ft @ 1700 rpm, its first year in the C/K range. C = 2WD, K = 4WD. Transmission pairing and diesel availability by weight class unverified.
1992 · GMC GMC Sierra C/K 2500
Engine: GM 6.5L Turbo Detroit Diesel V8
180 hp · 380 lb-ft
2WD / 4WD · 4L80-E automatic, NV4500 manual
GM's 1992 kit rates the turbocharged 6.5L (L65, 8600-12,000 lb GVWR) at 180 hp @ 3500 rpm and 380 lb-ft @ 1700 rpm, its first year in the C/K range. C = 2WD, K = 4WD. Transmission pairing and diesel availability by weight class unverified.
1993 · Chevrolet Chevrolet C/K 2500
Engine: GM 6.2L Detroit Diesel V8
150 hp · 280 lb-ft
2WD / 4WD · Transmission unknown
GM's 1993 kit rates the 6.2L LL4 (all except HD chassis and crew cab models) at 150 hp @ 3500 rpm and 280 lb-ft @ 2000 rpm, on the C/K Chassis-Cab powertrains chart. The 1989-1993 R/V-series overlap ended before 1993, so this row is C/K only. The 6.2 was rated 148 hp / 246 lb-ft in 1992, so the two years are not interchangeable. C = 2WD, K = 4WD. Transmission pairing and diesel availability by weight class unverified.
1993 · GMC GMC Sierra C/K 2500
Engine: GM 6.2L Detroit Diesel V8
150 hp · 280 lb-ft
2WD / 4WD · Transmission unknown
GM's 1993 kit rates the 6.2L LL4 (all except HD chassis and crew cab models) at 150 hp @ 3500 rpm and 280 lb-ft @ 2000 rpm, on the C/K Chassis-Cab powertrains chart. The 1989-1993 R/V-series overlap ended before 1993, so this row is C/K only. The 6.2 was rated 148 hp / 246 lb-ft in 1992, so the two years are not interchangeable. C = 2WD, K = 4WD. Transmission pairing and diesel availability by weight class unverified.
1993 · Chevrolet Chevrolet C/K 2500
Engine: GM 6.5L Turbo Detroit Diesel V8
190 hp · 380 lb-ft
2WD / 4WD · 4L80-E automatic, NV4500 manual
GM's 1993 kit rates the turbocharged 6.5L (RPO L65) at 190 hp @ 3400 rpm and 380 lb-ft @ 1700 rpm on C/K 3500 models, and 180 hp @ 3400 / 360 lb-ft @ 1700 on the HD chassis. The C/K 3500 figure is used as the highest offered in this row. It is taken from the C/K Chassis-Cab chart, the only 1993 chart found carrying ratings. C = 2WD, K = 4WD. Transmission pairing and diesel availability by weight class unverified.
1993 · GMC GMC Sierra C/K 2500
Engine: GM 6.5L Turbo Detroit Diesel V8
190 hp · 380 lb-ft
2WD / 4WD · 4L80-E automatic, NV4500 manual
GM's 1993 kit rates the turbocharged 6.5L (RPO L65) at 190 hp @ 3400 rpm and 380 lb-ft @ 1700 rpm on C/K 3500 models, and 180 hp @ 3400 / 360 lb-ft @ 1700 on the HD chassis. The C/K 3500 figure is used as the highest offered in this row. It is taken from the C/K Chassis-Cab chart, the only 1993 chart found carrying ratings. C = 2WD, K = 4WD. Transmission pairing and diesel availability by weight class unverified.
1994–1997 · Chevrolet Chevrolet C/K 2500
Engine: GM 6.5L Turbo Detroit Diesel V8
190 hp · 385 lb-ft
2WD / 4WD · 4L80-E automatic, NV4500 manual
GM's 1995 kit rates the heavy-duty turbocharged 6.5L (L65, above 8500 lb GVW) at 190 hp @ 3400 rpm and 385 lb-ft @ 1700 rpm, and GM's 1997 kit still shows L65 at 190 hp @ 3400 / 385 lb-ft @ 1800. The lighter-duty turbo (L56, 8500 lb GVW or under) was rated 180 hp @ 3400 / 360 lb-ft @ 1700; the L65 figure is used here as the highest offered in this row. The 1997 figure is taken from the C/K Chassis-Cab powertrains chart, the only 1997 chart found carrying the ratings; it is the same RPO L65 engine. C = 2WD, K = 4WD. Transmission pairing and diesel availability by weight class unverified.
1994–1997 · GMC GMC Sierra C/K 2500
Engine: GM 6.5L Turbo Detroit Diesel V8
190 hp · 385 lb-ft
2WD / 4WD · 4L80-E automatic, NV4500 manual
GM's 1995 kit rates the heavy-duty turbocharged 6.5L (L65, above 8500 lb GVW) at 190 hp @ 3400 rpm and 385 lb-ft @ 1700 rpm, and GM's 1997 kit still shows L65 at 190 hp @ 3400 / 385 lb-ft @ 1800. The lighter-duty turbo (L56, 8500 lb GVW or under) was rated 180 hp @ 3400 / 360 lb-ft @ 1700; the L65 figure is used here as the highest offered in this row. The 1997 figure is taken from the C/K Chassis-Cab powertrains chart, the only 1997 chart found carrying the ratings; it is the same RPO L65 engine. C = 2WD, K = 4WD. Transmission pairing and diesel availability by weight class unverified.
1994–1995 · Chevrolet Chevrolet C/K 2500
Engine: GM 6.5L Detroit Diesel V8 (naturally aspirated)
155 hp · 275 lb-ft
2WD / 4WD · Transmission unknown
GM's 1995 kit rates the naturally aspirated 6.5L (L49, 8500 lb GVW or under) at 155 hp @ 3600 rpm and 275 lb-ft @ 1700 rpm, and GM's 1994 ordering guide lists L49 as an available engine. The year range stops at 1995 because those are the years the engine could be confirmed: GM's 1998 C/K Pickup Specifications sheet lists only the two turbocharged diesels (L56 and L65), so the naturally aspirated engine was gone by 1998, and 1996-1997 availability could not be confirmed either way from the kits. The previous 1994-1998 range and its 155 hp / 275 lb-ft figure came from a third-party article. C = 2WD, K = 4WD. Transmission pairing and diesel availability by weight class unverified.
1994–1995 · GMC GMC Sierra C/K 2500
Engine: GM 6.5L Detroit Diesel V8 (naturally aspirated)
155 hp · 275 lb-ft
2WD / 4WD · Transmission unknown
GM's 1995 kit rates the naturally aspirated 6.5L (L49, 8500 lb GVW or under) at 155 hp @ 3600 rpm and 275 lb-ft @ 1700 rpm, and GM's 1994 ordering guide lists L49 as an available engine. The year range stops at 1995 because those are the years the engine could be confirmed: GM's 1998 C/K Pickup Specifications sheet lists only the two turbocharged diesels (L56 and L65), so the naturally aspirated engine was gone by 1998, and 1996-1997 availability could not be confirmed either way from the kits. The previous 1994-1998 range and its 155 hp / 275 lb-ft figure came from a third-party article. C = 2WD, K = 4WD. Transmission pairing and diesel availability by weight class unverified.
1998–2000 · Chevrolet Chevrolet C/K 2500
Engine: GM 6.5L Turbo Detroit Diesel V8
195 hp · 430 lb-ft
2WD / 4WD · 4L80-E automatic, NV4500 manual
GM's 1998 C/K Pickup Specifications sheet rates the L65 H.D. Turbo at 195 hp @ 3400 rpm and 430 lb-ft @ 1800 rpm, alongside the lighter-duty L56 Turbo at 180 hp @ 3400 / 360 lb-ft @ 1800. The 1999 kit repeats those figures and the 2000 kit gives 195 hp @ 3400 with 430 lb-ft @ 1800 on the automatic and 420 lb-ft @ 1800 on the manual. GM's 1998 sheet lists the L65 as optional on C/K2500 with the C6P heavy-duty GVW option and on C/K3500. The step up from 190/385 came with a set of mid-1997 changes GM describes as dual thermostats, a new water crossover, an increased-flow water pump, piston spray cooling, larger oil cooler lines and ceramic rollers in the injection pump. C = 2WD, K = 4WD. Transmission pairing and diesel availability by weight class unverified.
1998–2000 · GMC GMC Sierra C/K 2500
Engine: GM 6.5L Turbo Detroit Diesel V8
195 hp · 430 lb-ft
2WD / 4WD · 4L80-E automatic, NV4500 manual
GM's 1998 C/K Pickup Specifications sheet rates the L65 H.D. Turbo at 195 hp @ 3400 rpm and 430 lb-ft @ 1800 rpm, alongside the lighter-duty L56 Turbo at 180 hp @ 3400 / 360 lb-ft @ 1800. The 1999 kit repeats those figures and the 2000 kit gives 195 hp @ 3400 with 430 lb-ft @ 1800 on the automatic and 420 lb-ft @ 1800 on the manual. GM's 1998 sheet lists the L65 as optional on C/K2500 with the C6P heavy-duty GVW option and on C/K3500. The step up from 190/385 came with a set of mid-1997 changes GM describes as dual thermostats, a new water crossover, an increased-flow water pump, piston spray cooling, larger oil cooler lines and ceramic rollers in the injection pump. C = 2WD, K = 4WD. Transmission pairing and diesel availability by weight class unverified.
2001–2004 · Chevrolet Chevrolet Silverado 2500HD
Engine: Duramax 6.6L LB7 V8
300 hp · 520 lb-ft
2WD / 4WD · Allison 1000 automatic, 5-speed NV4500 manual
Launch of the Duramax in Silverado/Sierra HD, replacing the 6.5-liter. Transmission options as listed on the Silverado page (Allison 1000 automatic, NV4500 manual); exact pairing unverified. Mid-2004 changeover to the LLY.
2001–2004 · GMC GMC Sierra 2500HD
Engine: Duramax 6.6L LB7 V8
300 hp · 520 lb-ft
2WD / 4WD · Allison 1000 automatic, 5-speed NV4500 manual
Launch of the Duramax in Silverado/Sierra HD, replacing the 6.5-liter. Transmission options as listed on the Silverado page (Allison 1000 automatic, NV4500 manual); exact pairing unverified. Mid-2004 changeover to the LLY.
2004–2006 · Chevrolet Chevrolet Silverado 2500HD
Engine: Duramax 6.6L LLY V8
310 hp · 605 lb-ft
2WD / 4WD · Allison 1000 automatic, 5-speed NV4500 manual
Model year 2004.5 start; ratings as given for the automatic. Exact end year and rating differences for manual versions unverified.
2004–2006 · GMC GMC Sierra 2500HD
Engine: Duramax 6.6L LLY V8
310 hp · 605 lb-ft
2WD / 4WD · Allison 1000 automatic, 5-speed NV4500 manual
Model year 2004.5 start; ratings as given for the automatic. Exact end year and rating differences for manual versions unverified.
2006–2007 · Chevrolet Chevrolet Silverado 2500HD
Engine: Duramax 6.6L LBZ V8
360 hp · 650 lb-ft
2WD / 4WD · Allison 1000 six-speed automatic, 6-speed ZF S6-650 manual
2007 trucks built before the GMT900 launch were sold as 'Classic'. Six-speed Allison for 2006-2007 per one source.
2006–2007 · GMC GMC Sierra 2500HD
Engine: Duramax 6.6L LBZ V8
360 hp · 650 lb-ft
2WD / 4WD · Allison 1000 six-speed automatic, 6-speed ZF S6-650 manual
2007 trucks built before the GMT900 launch were sold as 'Classic'. Six-speed Allison for 2006-2007 per one source.
2007–2010 · Chevrolet Chevrolet Silverado 2500HD
Engine: Duramax 6.6L LMM V8
365 hp · 660 lb-ft
2WD / 4WD · Allison 1000 six-speed automatic
Started mid-2007 on the redesigned GMT900 trucks (2500HD/3500HD); the only Duramax offered 2007-2010. Diesel particulate filter added.
2007–2010 · GMC GMC Sierra 2500HD
Engine: Duramax 6.6L LMM V8
365 hp · 660 lb-ft
2WD / 4WD · Allison 1000 six-speed automatic
Started mid-2007 on the redesigned GMT900 trucks (2500HD/3500HD); the only Duramax offered 2007-2010. Diesel particulate filter added.
2011–2016 · Chevrolet Chevrolet Silverado 2500HD
Engine: Duramax 6.6L LML V8
397 hp · 765 lb-ft
2WD / 4WD · Allison 1000 six-speed automatic
LML ran 2011-2016 (2015-16 in the K2XX generation). DEF urea injection added. Rated rpm differs between sources.
2011–2016 · GMC GMC Sierra 2500HD
Engine: Duramax 6.6L LML V8
397 hp · 765 lb-ft
2WD / 4WD · Allison 1000 six-speed automatic
LML ran 2011-2016 (2015-16 in the K2XX generation). DEF urea injection added. Rated rpm differs between sources.
2017–2023 · Chevrolet Chevrolet Silverado 2500HD
Engine: Duramax 6.6L L5P V8
445 hp · 910 lb-ft
2WD / 4WD · Allison 1000 six-speed automatic (2017-2019), Allison 10-speed automatic (2020 onward)
Rating 445 hp / 910 lb-ft. Six-speed Allison through 2019, ten-speed from 2020.
2017–2023 · GMC GMC Sierra 2500HD
Engine: Duramax 6.6L L5P V8
445 hp · 910 lb-ft
2WD / 4WD · Allison 1000 six-speed automatic (2017-2019), Allison 10-speed automatic (2020 onward)
Rating 445 hp / 910 lb-ft. Six-speed Allison through 2019, ten-speed from 2020.
2024–2026 · Chevrolet Chevrolet Silverado 2500HD
Engine: Duramax 6.6L L5P V8
470 hp · 975 lb-ft
2WD / 4WD · Allison 10-speed automatic
Rating 470 hp / 975 lb-ft from 2024 (Wikipedia; Chevrolet's 2026 Silverado HD page lists the same for 2026).
2024–2026 · GMC GMC Sierra 2500HD
Engine: Duramax 6.6L L5P V8
470 hp · 975 lb-ft
2WD / 4WD · Allison 10-speed automatic
Rating 470 hp / 975 lb-ft from 2024 (Wikipedia; Chevrolet's 2026 Silverado HD page lists the same for 2026).