SKU: ATS303-900-4248

Allison Performance Valve Body

Ships From Manufacturer in 10-20 Days
Confirmed fitment below
YEARS
2001-2002
MAKE / MODEL
GM/Chevrolet/GMC / Silverado/Sierra
SERIES
2500HD/3500HD
ENGINE
6.6L Duramax LB7
Price
$879.99
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PRODUCT DETAIL

Key Features & Description

Features:

  • Fits 2001–2002 GM 2500HD and 3500HD
  • Designed for 6.6L Duramax LB7 engines
  • Compatible with Allison LCT1000 transmission
  • Improves shift quality and timing response
  • Increases hydraulic line pressure for better control
  • Includes performance A and B trim valves
  • Enhances transmission performance under load
  • Ideal for towing, racing, or daily driving
  • Sold as a complete performance upgrade kit
  • Proprietary internal design modifications included
  • Built by ATS Diesel for durability and precision

Make Your Allison Shift Like It Was Meant To

If you’re still running the stock valve body in your 2001–2002 GM 2500HD or 3500HD, you’re not getting everything your Allison transmission has to offer. The ATS 303-900-4248 Performance Valve Body transforms your shift feel, response, and drivability without requiring a full transmission overhaul. Whether you’re towing heavy, climbing steep grades, or just want a truck that feels tighter and more responsive, this upgrade delivers. Built for the 6.6L Duramax LB7, it installs into the Allison LCT1000 and instantly improves line pressure and shift timing so your truck reacts when you need it to. With proprietary modifications from ATS, this kit is purpose-built to offer the performance and reliability diesel owners demand. You’ll get firmer, cleaner shifts that reduce slippage and improve durability over time. This isn't just a part swap, it's a serious step toward getting the most out of your transmission.

Precision Calibrated Valve Control For Better Torque Handling

The ATS 303-900-4248 Allison Performance Valve Body is engineered to enhance the shifting performance of the Allison LCT1000 transmission in 2001–2002 GM 2500HD and 3500HD trucks equipped with the 6.6L Duramax LB7. This upgraded valve body features proprietary modifications to improve fluid control and pressure regulation throughout the transmission. By refining the A Trim and B Trim valves, ATS increases shift firmness and accuracy, minimizing slip and hesitation under load. The result is a more consistent and durable shift profile whether the truck is under heavy acceleration, towing, or hauling long distances. Increased line pressure offers improved torque holding capacity, reducing stress on clutches and improving transmission lifespan. The entire assembly is built to ATS Diesel’s exacting standards, developed through years of performance testing and refinement. Ideal for performance-minded truck owners or those with added power and torque, this kit provides real-world improvements without requiring a full transmission build. It’s a smart investment for better shift control, longer component life, and a more responsive driving experience.

Fits: 2001, 2002 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax LB7

Notes:

  • Fits 2001–2002 GM Silverado and Sierra 2500HD/3500HD
  • Designed specifically for the 6.6L Duramax LB7 engine
  • Compatible with Allison LCT1000 transmissions only
  • Includes upgraded A Trim and B Trim performance valves
  • Improves shift quality, timing, and line pressure
  • Recommended for towing, racing, and performance builds
  • Helps reduce clutch slippage and improve longevity
  • Sold as a complete performance valve body assembly
  • Developed by ATS Diesel with proprietary design upgrades
  • Professional installation is recommended for best results

 

FITMENT GUIDE

Exact Fitment — Verify Your Year

Year RangesYears
Make
Model
Series
Engine
2001-2002
GM/Chevrolet/GMC
Silverado/Sierra
2500HD/3500HD
6.6L Duramax LB7

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