Replace the under achieving factory air intake system in yourÂ 2001-2004 GM 6.6L Duramax LB7 with theÂ AEM 21-8013D Brute Force Intake System. The Brute Force Intake System is easily installed with commonly available tools and features aÂ tapered cylinder shaped AEM Dryflow air filter that consists of an oil-free, synthetic filter media that can be used for up to 100,000 miles before it needs to be cleaned. The air filter and air intake housing is non restrictive to promote increased horsepower and torque gains. The air filter is located in the in the original air box space and is surrounded by a heat shield that is engineered to lower the air intake temperature to increase horsepower even further.Â Features: Increased Horsepower Easy to Install Using Commonly Available Tools Turned and Dyno-Tested to Improve Acceleration and Engine SoundÂ Â CA Residents: CARB E.O. Number on file - LEGAL for use in California.