The Flowmaster American Thunder Cat-back Exhaust System is engineered to deliver aggressive performance, refined tone, and long-lasting durability for 2020–2026 Chevrolet Silverado and GMC Sierra 2500HD/3500HD trucks equipped with the 6.6L gas engine. This bolt-on, emissions-legal system provides an aggressive to moderate sound level inside and outside the vehicle while improving exhaust flow and overall performance.

Designed specifically for Crew Cab models with the 6.5-foot (Standard) bed, this system uses a robust 50 Series HD muffler with Delta Flow technology, coupled with large dual 3.00-inch 409 stainless steel mandrel-bent tailpipes. The kit includes both dual rear and dual side exit tailpipe configurations, making it ideal for towing applications that require angled side exits behind the rear wheels.

Fitment 

• Fits 2020–2026 Chevrolet Silverado 2500HD

• Fits 2020–2026 Chevrolet Silverado 3500HD

• Fits 2020–2026 GMC Sierra 2500HD

• Fits 2020–2026 GMC Sierra 3500HD

• Fits 6.6L gas engine

• Fits Crew Cab

• Fits 6.5 ft Standard Bed

• Fits 159-inch wheelbase

• Will not fit models equipped with a 5th wheel tow hitch

Features

• Mandrel-bent 16-gauge tubing for maximum exhaust flow

• Uses factory hanger locations for fast and easy installation

• 50 Series HD muffler with Delta Flow Technology

• 409 stainless steel construction for long service life

• Increased performance and improved exhaust flow

• Multiple tailpipe exits included (dual rear and dual side)

• Large 3.00-inch dual tailpipes

• Deep, powerful exterior exhaust sound

• Lifetime Limited Warranty

• Flowmaster quality and performance

The exhaust is finished with dual 4.00-inch polished 304 stainless steel tips, adding a clean high-end appearance. Installation is simple thanks to factory hanger compatibility, and all necessary parts and hardware are included. Covered by Flowmaster’s Lifetime Limited Warranty for long-term confidence and value.