SKU: ATS309-854-4272

Stage 5 Allison LCT1000 Crate Transmission

Ships From Manufacturer in 15-20 Days
Confirmed fitment below
YEARS
2003-2004
MAKE / MODEL
GM/Chevrolet/GMC / Silverado/Sierra
SERIES
2500HD/3500HD
ENGINE
6.6L Duramax LB7/6.6L Duramax LLY
Price
$9,084.99
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PRODUCT DETAIL

Key Features & Description

Features:

  • Fits 2003-2004 6.6L LB7 Duramax 4WD
  • Includes upgraded Allison LCT1000 transmission
  • Five Star torque converter for better torque transfer
  • Deep transmission pan for improved cooling
  • Billet input shaft for added durability
  • Billet output and intermediate shafts included
  • ATS Co-Pilot controller for enhanced shift control
  • Designed for towing and high performance builds
  • Handles high torque and heavy loads
  • Complete Stage 5 performance transmission package

Serious Strength for Your LB7 Duramax Build

If you're driving a 2003 to early 2004 Silverado or Sierra HD with the 6.6L LB7 Duramax and your power goals are climbing, the ATS Stage 5 Allison LCT1000 Crate Transmission is the kind of upgrade that brings everything together. This transmission package is built for 4WD models and is designed to replace your factory setup with something far more capable. At the heart of it is ATS’s performance-built Allison LCT1000, built specifically to handle the demands of towing, tuning, and spirited driving. It includes the ATS Five Star torque converter, engineered to improve torque multiplication and help your truck move with confidence under load.

Built Tough with Smart Performance Enhancements

Inside the transmission, ATS includes billet input, output, and intermediate shafts to handle higher horsepower and torque levels without flexing or failing. A deep transmission pan helps control fluid temperatures during long hauls or heavy-duty operation. The package also includes the ATS Co-Pilot Transmission Controller, which refines your shift strategies and line pressure in real time to match your driving needs. Whether you’re building a reliable workhorse or looking to stretch your LB7’s capabilities, this crate transmission is designed to give you long-term durability and smooth, confident power delivery with every gear change. It’s a complete solution for truck owners who expect more out of their driveline.

Fits: 2003, 2004 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax LB7 4WD

FITMENT GUIDE

Exact Fitment — Verify Your Year

Year RangesYears
Make
Model
Series
Engine
2003-2004
GM/Chevrolet/GMC
Silverado/Sierra
2500HD/3500HD
6.6L Duramax LB7/6.6L Duramax LLY

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