2004.5-2005 GM 2500HD/3500HD 6.6L LL 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

Availability
Manufacturer
Make
Model
Year
Price
$0
$27,677.69
Rating
Loading products...
Filter
265 products
Sort by:
Best selling
Availability
Manufacturer
Make
Model
Year
Price
$0
$27,677.69
Rating
PPE 118021230 Valve Cover Kit with Pillars - Polished | 2005-2010 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax
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
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
PPE 114001000 Internal Oil Cooler Removal Kit | 2001-2016 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax
PPE 114001000 Internal Oil Cooler Removal Kit | 2001-2016 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax

PPE

PPE 114001000 Internal Oil Cooler Removal Kit | 2001-2016 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax

SKU: PPE114001000
$269.99
PPE 113061094 Idler Pulley 3 inch OD OEM Size | 2001-2010 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax
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
$35.99
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 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
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
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-DMAX-OC-BLU Oil Cap Blue | 2001-2016 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax
Fleece FPE-DMAX-OC-BLU Oil Cap Blue | 2001-2016 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax
Fleece FPE-DMAX-OC-BLU Oil Cap Blue | 2001-2016 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax

Fleece Performance Products

Fleece FPE-DMAX-OC-BLU Oil Cap Blue | 2001-2016 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax

SKU: FLCFPE-DMAX-OC-BLU
$39.99
Fleece FPE-BRAB-D1 32V Rocker Bridges | 2001-2016 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax
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
Edge 98005 CTS2 Pod Adapter | Universal
Edge 98005 CTS2 Pod Adapter | Universal

Edge Products

Edge 98005 CTS2 Pod Adapter | Universal

SKU: EDG98005
$29.60
Edge 98616 EAS Control Kit | Universal
Edge 98616 EAS Control Kit | Universal
Edge 98616 EAS Control Kit | Universal

Edge Products

Edge 98616 EAS Control Kit | Universal

SKU: EDG98616
$423.95
Edge 98602 EAS Starter Cable for CS2/CTS2/CTS3 | Universal
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
$74.89
Mahle CB1805P P-Series Rod Bearing | 2001-2016 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax
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
Mahle CB1805H Standard Rod Bearing Kit | 2001-2016 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax
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
Cometic C15043 17-Bolt Fiber Oil Pan Gasket Lower - .060 inch | 2001-2016 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax
Cometic C15043 17-Bolt Fiber Oil Pan Gasket Lower - .060 inch | 2001-2016 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax

Cometic

Cometic C15043 17-Bolt Fiber Oil Pan Gasket Lower - .060 inch | 2001-2016 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax

SKU: COMC15043
$19.03
ARP 900-0550 4.005 Bore Ring Compressor | 2001-2016 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax
ARP 900-0550 4.005 Bore Ring Compressor | 2001-2016 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax

ARP

ARP 900-0550 4.005 Bore Ring Compressor | 2001-2016 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax

SKU: ARP900-0550
$97.13
Edge 98607 0-100 PSIG EAS Pressure Sensor | Universal
Edge 98607 0-100 PSIG EAS Pressure Sensor | Universal

Edge Products

Edge 98607 0-100 PSIG EAS Pressure Sensor | Universal

SKU: EDG98607
$212.95
Industrial 44B801 130lb Valve Spring Kit | 2001-2016 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax
Industrial 44B801 130lb Valve Spring Kit | 2001-2016 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax
Industrial 44B801 130lb Valve Spring Kit | 2001-2016 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax
Industrial 44B801 130lb Valve Spring Kit | 2001-2016 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax
Industrial 44B801 130lb Valve Spring Kit | 2001-2016 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax

Industrial Injection

Industrial 44B801 130lb Valve Spring Kit | 2001-2016 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax

SKU: IIS44B801
$873.92
Wehrli 100645 OEM Placement Coolant Tank Kit | 2001-2007 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax
Wehrli 100645 OEM Placement Coolant Tank Kit | 2001-2007 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax
Wehrli 100645 OEM Placement Coolant Tank Kit | 2001-2007 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax
Wehrli 100645 OEM Placement Coolant Tank Kit | 2001-2007 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax
Wehrli 100645 OEM Placement Coolant Tank Kit | 2001-2007 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax

Wehrli Custom Fab

Wehrli 100645 OEM Placement Coolant Tank Kit | 2001-2007 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax

SKU: WCF100645-GB
From $474.33
Gator Fasteners MSK667Y Main Stud Kit | 2001-2005 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax
Gator Fasteners MSK667Y Main Stud Kit | 2001-2005 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax
Gator Fasteners MSK667Y Main Stud Kit | 2001-2005 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax
Gator Fasteners MSK667Y Main Stud Kit | 2001-2005 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax
Gator Fasteners MSK667Y Main Stud Kit | 2001-2005 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax

Gator Fasteners

Gator Fasteners MSK667Y Main Stud Kit | 2001-2005 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax

SKU: GTFMSK667Y
$279.99
$350
Fluidampr 890101 External Balance Steel Black Zinc Finish O.D. 8-3/8 inch Performance Damper | 01-05 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax
Fluidampr 890101 External Balance Steel Black Zinc Finish O.D. 8-3/8 inch Performance Damper | 01-05 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax

Fluidampr

Fluidampr 890101 External Balance Steel Black Zinc Finish O.D. 8-3/8 inch Performance Damper | 01-05 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax

SKU: FLU890101
$574.82
Tuner DT8120010104000 Street Tune incl EFI Live Spade | 2004.5-2005 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax LLY
Tuner DT8120010104000 Street Tune incl EFI Live Spade | 2004.5-2005 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax LLY

Duramax Tuner

Tuner DT8120010104000 Street Tune incl EFI Live Spade | 2004.5-2005 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax LLY

SKU: DMTDT8120010104000
$808
Tuner DT1120010008000 Transmission Tune Only for EFI Live Spade | 2004.5-2005 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax LLY
Tuner DT1120010008000 Transmission Tune Only for EFI Live Spade | 2004.5-2005 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax LLY

Duramax Tuner

Tuner DT1120010008000 Transmission Tune Only for EFI Live Spade | 2004.5-2005 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax LLY

SKU: DMTDT1120010008000
$300
PPE 115010060 Zilla Carbon Fiber Turbo Inlet Upgrade (Twill Weaved) | 2004.5-2005 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax LLY
PPE 115010060 Zilla Carbon Fiber Turbo Inlet Upgrade (Twill Weaved) | 2004.5-2005 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax LLY
PPE 115010060 Zilla Carbon Fiber Turbo Inlet Upgrade (Twill Weaved) | 2004.5-2005 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax LLY
PPE 115010060 Zilla Carbon Fiber Turbo Inlet Upgrade (Twill Weaved) | 2004.5-2005 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax LLY
PPE 115010060 Zilla Carbon Fiber Turbo Inlet Upgrade (Twill Weaved) | 2004.5-2005 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax LLY
PPE 115010060 Zilla Carbon Fiber Turbo Inlet Upgrade (Twill Weaved) | 2004.5-2005 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax LLY

PPE

PPE 115010060 Zilla Carbon Fiber Turbo Inlet Upgrade (Twill Weaved) | 2004.5-2005 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax LLY

SKU: PPE115010060
$197.99
$219.99

FREE SHIPPING ON ALL
ORDERS OVER $70

PRICE MATCH GUARANTEE

BUILD NOW, PAY LATER
FINANCING OPTIONS

30-DAY RETURN SATISFACTION GUARANTEE

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

Can We Help You Find Something?

Give us a call: +1-208-719-7400

Chat With Us