2004.5-2005 GM 2500HD/3500HD 6.6L LLY Duramax Engine & Performance

2004.5-2005 GM 2500HD/3500HD 6.6L LLY Duramax Crate Engines

Crate Engines

2004.5-2005 GM 2500HD/3500HD 6.6L LLY Duramax Gaskets, Gasket Kits & Bearings

Gaskets

2004.5-2005 GM 2500HD/3500HD 6.6L LLY Duramax Glow Plugs

Glow Plugs

2004.5-2005 GM 2500HD/3500HD 6.6L LLY Duramax Head Studs & Main Studs

Head Studs & Main Studs

2004.5-2005 GM 2500HD/3500HD 6.6L LLY Duramax Heads & Valve Train

Heads & Valve Train

2004.5-2005 GM 2500HD/3500HD 6.6L LLY Duramax Motor Mounts

Motor Mounts

2004.5-2005 GM 2500HD/3500HD 6.6L LLY Duramax Oil Pans

Oil Pans

2004.5-2005 GM 2500HD/3500HD 6.6L LLY Duramax Radiators & Cooling Upgrades

Radiators & Cooling Upgrades

2004.5-2005 GM 2500HD/3500HD 6.6L LLY Duramax Rebuild Kits & Internal Parts

Rebuild Kits & Internal Parts

2004.5-2005 GM 2500HD/3500HD 6.6L LLY Duramax Rods, Pistons, Cams & More

Rods/Pistons/Cams & More

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PPE 114025010 Check Valve Crankcase Breather Filter Kit | 2004.5-2010 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax
IN STOCK
PPE 114025010 Check Valve Crankcase Breather Filter Kit | 2004.5-2010 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax

PPE

PPE 114025010 Check Valve Crankcase Breather Filter Kit | 2004.5-2010 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax

SKU: PPE114025010
$44.99
PPE 114010000 Oil Centrifuge Filtration Kit | 2001-2005 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax
IN STOCK
PPE 114010000 Oil Centrifuge Filtration Kit | 2001-2005 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax

PPE

PPE 114010000 Oil Centrifuge Filtration Kit | 2001-2005 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax

SKU: PPE114010000
$449.99
Merchant 98045057 Grade C Right Head Gasket | 2001-2016 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax
Merchant 98045057 Grade C Right Head Gasket | 2001-2016 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax

Merchant Automotive

Merchant 98045057 Grade C Right Head Gasket | 2001-2016 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax

SKU: MAT98045057
$99.72
Industrial 449E01 Stage 1 Pushrods | 2001-2010 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax
Industrial 449E01 Stage 1 Pushrods | 2001-2010 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax

Industrial Injection

Industrial 449E01 Stage 1 Pushrods | 2001-2010 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax

SKU: IIS449E01
$29.05
Wagler CRC6.6ST Street Fighter Connecting Rods | 2001-2016 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax
Wagler CRC6.6ST Street Fighter Connecting Rods | 2001-2016 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax
Wagler CRC6.6ST Street Fighter Connecting Rods | 2001-2016 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax

Wagler Competition Products

Wagler CRC6.6ST Street Fighter Connecting Rods | 2001-2016 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax

SKU: WCPCRC6.6ST
$1,950
PPE 518001000 Weld-On Billet Radiator Neck | Universal
IN STOCK
PPE 518001000 Weld-On Billet Radiator Neck | Universal
PPE 518001000 Weld-On Billet Radiator Neck | Universal

PPE

PPE 518001000 Weld-On Billet Radiator Neck | Universal

SKU: PPE518001000
$22.49
PPE 314030212 Oil Cooler Gasket Kit | 2003-2007 Ford F250/F350 6.0L Powerstroke
IN STOCK
PPE 314030212 Oil Cooler Gasket Kit | 2003-2007 Ford F250/F350 6.0L Powerstroke

PPE

PPE 314030212 Oil Cooler Gasket Kit | 2003-2007 Ford F250/F350 6.0L Powerstroke

SKU: PPE314030212
$35.99
PPE 128059160 Neodymium Magnet - Ring Style | 2001-2019 Allison 1000
PPE 128059160 Neodymium Magnet - Ring Style | 2001-2019 Allison 1000
PPE 128059160 Neodymium Magnet - Ring Style | 2001-2019 Allison 1000
PPE 128059160 Neodymium Magnet - Ring Style | 2001-2019 Allison 1000

PPE

PPE 128059160 Neodymium Magnet - Ring Style | 2001-2019 Allison 1000

SKU: PPE128059160
$13.49
PPE 118026010 Stage 1 Performance Camshaft - Standard Fire | 2001-2016 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax
IN STOCK
PPE 118026010 Stage 1 Performance Camshaft - Standard Fire | 2001-2016 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax
PPE 118026010 Stage 1 Performance Camshaft - Standard Fire | 2001-2016 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax
PPE 118026010 Stage 1 Performance Camshaft - Standard Fire | 2001-2016 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax

PPE

PPE 118026010 Stage 1 Performance Camshaft - Standard Fire | 2001-2016 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax

SKU: PPE118026010
$629.99
$699.99
SAVE $70
PPE 118021418 Valve Cover Kit with out Pillars | 2004-2010 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax
PPE 118021418 Valve Cover Kit with out Pillars | 2004-2010 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax

PPE

PPE 118021418 Valve Cover Kit with out Pillars | 2004-2010 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax

SKU: PPE118021418
$287.99
PPE 118021412 Valve Cover Kit with out Pillars - Red | 2004.5-2010 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax
IN STOCK
PPE 118021412 Valve Cover Kit with out Pillars - Red | 2004.5-2010 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax

PPE

PPE 118021412 Valve Cover Kit with out Pillars - Red | 2004.5-2010 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax

SKU: PPE118021412
$287.99
PPE 118021230 Valve Cover Kit with Pillars - Polished | 2005-2010 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax
IN STOCK
PPE 118021230 Valve Cover Kit with Pillars - Polished | 2005-2010 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax

PPE

PPE 118021230 Valve Cover Kit with Pillars - Polished | 2005-2010 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax

SKU: PPE118021230
$305.99
PPE 114051086 Engine Oil Fill Delete Plug (Raw) | 2001-2019 GM Silverado/Sierra 2500HD/3500HD
IN STOCK
PPE 114051086 Engine Oil Fill Delete Plug (Raw) | 2001-2019 GM Silverado/Sierra 2500HD/3500HD
PPE 114051086 Engine Oil Fill Delete Plug (Raw) | 2001-2019 GM Silverado/Sierra 2500HD/3500HD

PPE

PPE 114051086 Engine Oil Fill Delete Plug (Raw) | 2001-2019 GM Silverado/Sierra 2500HD/3500HD

SKU: PPE114051086
$17.09
$18.99
SAVE $1.90
PPE 113061094 Idler Pulley 3 inch OD OEM Size | 2001-2010 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax
IN STOCK
PPE 113061094 Idler Pulley 3 inch OD OEM Size | 2001-2010 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax

PPE

PPE 113061094 Idler Pulley 3 inch OD OEM Size | 2001-2010 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax

SKU: PPE113061094
$47.69
PPE 110090050 Valve Springs, Retainers, Keepers Complete Kit | 2001-2016 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax
IN STOCK
PPE 110090050 Valve Springs, Retainers, Keepers Complete Kit | 2001-2016 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax
PPE 110090050 Valve Springs, Retainers, Keepers Complete Kit | 2001-2016 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax

PPE

PPE 110090050 Valve Springs, Retainers, Keepers Complete Kit | 2001-2016 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax

SKU: PPE110090050
$539.99
Mishimoto MMOC-F HD Transmission Cooler with Fan | Universal
IN STOCK
Mishimoto MMOC-F HD Transmission Cooler with Fan | Universal
Mishimoto MMOC-F HD Transmission Cooler with Fan | Universal
Mishimoto MMOC-F HD Transmission Cooler with Fan | Universal
Mishimoto MMOC-F HD Transmission Cooler with Fan | Universal

Mishimoto

Mishimoto MMOC-F HD Transmission Cooler with Fan | Universal

SKU: MIMMMOC-F
$199.95
$209.95
SAVE $10
Gator Fasteners HSK66-CS Competition 625 Series Head Stud Kit | 2001-2016 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax
Gator Fasteners HSK66-CS Competition 625 Series Head Stud Kit | 2001-2016 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax

Gator Fasteners

Gator Fasteners HSK66-CS Competition 625 Series Head Stud Kit | 2001-2016 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax

SKU: GTFHSK66-CS
$1,419.99
Mahle GS33504 Cylinder Head Bolts | 2001-2010 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax
IN STOCK
Mahle GS33504 Cylinder Head Bolts | 2001-2010 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax

Mahle

Mahle GS33504 Cylinder Head Bolts | 2001-2010 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax

SKU: MCIGS33504
$92.47
Fleece FPE-BRAB-D1 32V Rocker Bridges | 2001-2016 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax
IN STOCK
Fleece FPE-BRAB-D1 32V Rocker Bridges | 2001-2016 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax

Fleece Performance Products

Fleece FPE-BRAB-D1 32V Rocker Bridges | 2001-2016 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax

SKU: FLCFPE-BRAB-D1
$512.54
Edge 98005 CTS2 Pod Adapter | Universal
IN STOCK
Edge 98005 CTS2 Pod Adapter | Universal
Edge 98005 CTS2 Pod Adapter | Universal

Edge Products

Edge 98005 CTS2 Pod Adapter | Universal

SKU: EDG98005
$30.78
$34.63
SAVE $3.85
Edge 98616 EAS Control Kit | Universal
IN STOCK
Edge 98616 EAS Control Kit | Universal
Edge 98616 EAS Control Kit | Universal

Edge Products

Edge 98616 EAS Control Kit | Universal

SKU: EDG98616
$292.95
$506.95
SAVE $214
Edge 98602 EAS Starter Cable for CS2/CTS2/CTS3 | Universal
IN STOCK
Edge 98602 EAS Starter Cable for CS2/CTS2/CTS3 | Universal
Edge 98602 EAS Starter Cable for CS2/CTS2/CTS3 | Universal

Edge Products

Edge 98602 EAS Starter Cable for CS2/CTS2/CTS3 | Universal

SKU: EDG98602
$77.89
$87.95
SAVE $10.06
Mahle CB1805P P-Series Rod Bearing | 2001-2016 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax
IN STOCK
Mahle CB1805P P-Series Rod Bearing | 2001-2016 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax

Mahle

Mahle CB1805P P-Series Rod Bearing | 2001-2016 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax

SKU: MCICB1805P
$20
$20.60
SAVE $0.60
Mahle CB1805H Standard Rod Bearing Kit | 2001-2016 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax
IN STOCK
Mahle CB1805H Standard Rod Bearing Kit | 2001-2016 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax

Mahle

Mahle CB1805H Standard Rod Bearing Kit | 2001-2016 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax

SKU: MCICB1805H
$35.52
$44.30
SAVE $8.78

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DIESEL TRUCK EXPERTS STANDING BY

The 6.6L Duramax LLY under the hood of your 2004.5-2005 GM Sierra/Silverado 2500/3500 may be one of the best and most efficient engines out there, but even the toughest trucks have some power and performance waiting to be unleashed through various performance modifications. Here at Alligator Performance, we carry a selection of cold air intakes, tuners, fuel upgrades, and turbo upgrades to help you get the most out of your diesel engine. Many of these upgrades like the cold air intakes and fuel upgrades even help promote component longevity so you can enjoy long-lasting and consistent performance without compromise. After you've added a few engine upgrades to your custom build, be sure to check out our premium 2004.5-2005 GM 6.6L Duramax LLY Transmission Upgrades to compliment the increase in power you're throwing down! GM Duramax Fitments: 2004, 2005 GM 6.6L Duramax. Submodel Fitments: WT, Custom, LT, LTZ, High Country, 1LT, 2LT, Pro, SLE, SLT, AT4, Denali. Some exceptions apply, please see individual product pages for specific fitments.

GM Duramax>2004.5-2005 6.6L LLY
Tuners & Monitors
Cooling Upgrades
Head Studs & Main Studs
Rods, Pistons & Cams
Heads & Valve Train

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