Take your 2001-2004 GM 6.6L Duramax LB7 and upgrade its underwhelming factory intake system with the theÂ AEM 21-9021D Brute Force HD Intake. The Brute Force Intake is easy to install and clean due to it's synthetic oil free filter media. In order to keep the air cool and increase horsepower, the air filter is housed in the original air box space and is surrounded by a heat shield. The intake tubing is designed with durable aluminum that is powder coated in a gunmetal gray finish for an awesome look.Â Features: Increased Horsepower Easy to Install Using Commonly Available Tools Tuned and Dyno-Tested to Improve Acceleration and Engine Sound CA Residents: CARB E.O. Number on file - LEGAL for use in California.