Description
Overview
The Flowmaster American Thunder Cat-back Exhaust System is a bolt-on, emissions-legal upgrade custom designed for 1996-1999 Chevrolet Silverado and GMC Sierra 1500 trucks equipped with the 5.7L engine. Built for the driver who wants a mild to moderate sound level inside and outside the cab, it delivers all the performance benefits you expect from Flowmaster while keeping street manners in check. This system is CARB (California) compliant, so you get real gains without stepping outside the rules.
At the heart of the system is a flanged inlet with dual pipes that feed into a Scavenger Series Y-collector, engineered for maximum scavenging and meaningful torque gains. From there, exhaust flow transitions into a large 3.00-inch mandrel-bent aluminized steel inlet pipe and into a 70 Series Big Block II performance muffler (part number 53072) for a deep, mellow tone that never drones.
Key Benefits
Mandrel-bent tubing maintains a smooth, consistent 3.00-inch diameter throughout, promoting efficient flow and helping the 5.7L engine breathe more freely. The single aluminized steel tailpipe is finished with a turndown-style exit behind the right rear wheel and takes advantage of the factory hanger locations, so the fit looks and feels factory-correct.
- Custom-engineered cat-back system for 1996-1999 Silverado / Sierra 1500 with the 5.7L engine
- Moderate sound level with a deep, mellow tone thanks to the 70 Series Big Block II muffler
- Scavenger Series Y-collector for maximum scavenging and torque gains
- 3.00-inch mandrel-bent aluminized steel piping for smooth, unrestricted flow
- CARB (California) compliant and emissions-legal (Emission Code 5)
- Includes all necessary parts and hardware for a straightforward at-home install
Configuration & What’s Included
This is a single tailpipe setup with a turndown exit and the muffler included, so the core system arrives ready to bolt on. The exhaust tip is sold separately, giving you the freedom to finish the look exactly how you want. Note that a heat shield is not included with this system. Every component is designed to work together, from the flanged dual-pipe inlet through the Y-collector, muffler, and silver-finished piping.
Fitment
Engineered specifically for the 1996-1999 Chevrolet Silverado and GMC Sierra 1500 with the 5.7L engine in 2WD configuration. Because the system uses the factory hanger locations and includes all necessary hardware, installation is a quick, straightforward job you can tackle at home.
Backed by Flowmaster’s 3-year Limited Warranty, the American Thunder cat-back combines proven torque-building design with the deep, refined sound that has made the Flowmaster name legendary among truck owners.
