Description
Overview
The Flowmaster American Thunder Cat-back Exhaust System is built for the truck owner who wants a subtle custom appearance paired with all the benefits a genuine Flowmaster Cat-back system delivers. Engineered specifically for the 2001-2006 (2007 Classic) Chevrolet Silverado and GMC Sierra 2500HD/3500HD equipped with the 6.0L or 8.1L engine, this system uses a dual inlet muffler design to produce a moderate interior tone and a deep, powerful exterior note. It’s the ideal choice for the enthusiast who wants their performance to be heard without crossing the line into obnoxious.
Sound and Performance
At the heart of the system is a dual inlet 50 Series Big Block muffler that bolts directly to the back of the catalytic converter. This muffler is tuned for a deep, aggressive character that stays refined at cruise, so you get a rich growl under throttle while keeping the cab comfortable on long hauls. As with every Flowmaster system, the design is engineered to improve throttle response, power, and mileage, turning a simple bolt-on into a genuine performance upgrade.
Build and Materials
The custom bent 3.50-inch 409 stainless steel tailpipe is shaped to use the factory hanger locations for a clean, straightforward installation. It exits out behind the right side rear wheel, a layout that is ideal for towing, and is finished with a large 4.00-inch polished 304 stainless steel tip embossed with the Flowmaster logo. A large, custom-formed aluminum heat shield with stainless clamps mounts directly to the muffler body for a finished, purpose-built look. Every system is designed for an easy fit and includes the necessary parts and hardware to get the job done.
- Dual inlet 50 Series Big Block muffler (muffler included) with a 3.00-inch inlet
- Custom bent 3.50-inch 409 stainless steel single tailpipe using factory hanger locations
- Large 4.00-inch polished 304 stainless steel tip embossed with the Flowmaster logo
- Right-side rear exit behind the wheel, ideal for towing
- Custom-formed aluminum heat shield with stainless clamps that attaches to the muffler body
- Aggressive sound level with a moderate interior tone and deep exterior note
Fitment
This American Thunder system is designed for the 2001-2006 (and 2007 Classic) Chevrolet Silverado and GMC Sierra 2500HD/3500HD with the 6.0L or 8.1L engine and a dual inlet muffler configuration. It is a 4WD-oriented, cat-back setup that attaches at the rear of the catalytic converter. The system is CARB (California) compliant with Emission Code 5, and carries a California Proposition 65 warning. Choose this system when you want the proven Flowmaster combination of sound, style, and driveability engineered specifically for your heavy-duty GM truck.
