Description
Overview
The Flowmaster American Thunder Cat-back Exhaust System is built for the enthusiast who wants a subtle custom appearance paired with all the benefits a genuine Flowmaster cat-back system delivers. Engineered for the 2001-2006 (2007 Classic) Chevrolet Silverado and GMC Sierra 2500HD/3500HD equipped with the 6.0L or 8.1L engine and a dual inlet muffler, this system strikes the balance between refinement and attitude — a moderate interior tone matched to a deep, powerful exterior note for drivers who want their performance to be heard.
At the heart of the system is the dual inlet 50 Series Big Block muffler, which attaches to the back of the catalytic converter to produce that signature deep, powerful sound without ever becoming obnoxious. It’s the ideal choice for owners who want an aggressive presence on the street while keeping cabin comfort in check on longer drives and while towing.
Key Benefits
Like every Flowmaster system, the American Thunder is about more than sound. The design promotes improved throttle response, added power, and better mileage, giving your Silverado or Sierra HD a genuine performance upgrade you can both hear and feel behind the wheel.
- Dual inlet 50 Series Big Block muffler for a deep, powerful, yet controlled tone
- Custom bent 3.50-inch aluminized steel tailpipe routed to the factory hanger locations
- Single tailpipe exit behind the right side rear wheel — ideal for towing setups
- Large 4.00-inch polished 304 stainless steel tip embossed with the Flowmaster logo
- Large custom formed aluminum heat shield with stainless clamps that mounts directly to the muffler body
- U-Bolt clamping and all necessary parts and hardware included for a straightforward install
Fit, Finish & Installation
The custom bent 3.50-inch aluminized steel tailpipe uses the factory hanger locations for an easy, bolt-in installation, then exits out behind the right side rear wheel — a layout purpose-built with towing in mind. A large custom formed aluminum heat shield with stainless clamps attaches directly to the muffler body, and the whole system is finished off with a large 4.00-inch polished 304 stainless steel tip embossed with the Flowmaster logo for a clean, custom look at the rear of the truck.
This system carries a 3.00-inch inlet diameter, U-Bolt clamping, and a silver pipe finish. It is CARB (California) compliant with Emission Code 5, making it a smart choice for 2WD owners who want a legal, great-sounding upgrade. Designed for an easy fit, it includes all necessary parts and hardware to complete the job.
Warning: This product carries a California Proposition 65 warning.
