Product Description
The ATS 309-854-4272 Stage 5 Allison LCT1000 Transmission Package is a top-tier performance upgrade designed for 2003 to early 2004 GM Silverado and Sierra trucks equipped with the 6.6L LB7 Duramax diesel engine and 4WD drivetrain. Built to handle extreme horsepower, aggressive tuning, and heavy towing demands, this Stage 5 package delivers maximum strength, durability, and performance.
This package includes a fully built ATS Stage 5 Allison LCT1000 transmission, ATS Five Star torque converter, and ATS deep transmission pan. ATS upgrades the Allison platform with billet internal components, increased clutch capacity, and proprietary modifications that dramatically improve torque holding capability and transmission longevity under high-load conditions.
The included Five Star torque converter enhances torque multiplication and efficiency, while the deep transmission pan increases fluid capacity and cooling performance. Together, these components create a transmission system capable of handling high-performance builds, competition use, and extreme towing applications.
This package is ideal for Duramax owners pushing beyond stock power levels who need a proven transmission solution that delivers reliability without compromise.
FAQ
What is included in the ATS Stage 5 package?
This package includes a fully built ATS Stage 5 Allison LCT1000 transmission, Five Star torque converter, and deep transmission pan.
What makes the Stage 5 different from lower stages?
Stage 5 units include upgraded billet components, increased clutch capacity, and are designed for high horsepower and extreme-duty applications.
Is this transmission suitable for high horsepower builds?
Yes. Stage 5 is designed for trucks with significant power upgrades, competition use, and heavy towing.
Will this improve towing performance?
Absolutely. Increased torque capacity and improved cooling make it ideal for heavy towing and hauling.
Does this fit all LB7 Duramax trucks?
This package fits 2003 to early 2004 LB7 trucks with 4WD and Allison LCT1000 transmissions.
FITMENT
2003 Chevrolet Silverado 2500HD/3500HD 6.6L LB7 Duramax Diesel 4WD
2004 (Early) Chevrolet Silverado 2500HD/3500HD 6.6L LB7 Duramax Diesel 4WD
2003 GMC Sierra 2500HD/3500HD 6.6L LB7 Duramax Diesel 4WD
2004 (Early) GMC Sierra 2500HD/3500HD 6.6L LB7 Duramax Diesel 4WD
Specifications for ATS 309-854-4272
| Specification | Details |
|---|---|
| Part Number | 309-854-4272 |
| Product Name | ATS Stage 5 Allison LCT1000 Transmission Package |
| Transmission Model | Allison LCT1000 |
| Engine Fitment | 6.6L LB7 Duramax Diesel |
| Vehicle Fitment | 2003 - Early 2004 GM 2500HD/3500HD |
| Drive Configuration | 4WD |
| Included Components | Stage 5 Built Transmission, Five Star Torque Converter, Deep Transmission Pan |
| Performance Level | Stage 5 (Extreme Duty / High Horsepower) |
| UPC | Not Available |
| GTIN | Not Available |
| Shipping Information | Freight Shipping Required |
| Core Charge | Core Charge Applies |
| Prop 65 | WARNING: Cancer and Reproductive Harm |
