Description
Overview
The Flowmaster American Thunder Crossmember-Back Exhaust System is engineered to deliver serious performance and an unmistakable, aggressive exhaust note for 1968-1972 GM A-Bodies equipped with a V8. Purpose-built for high horsepower and large cubic inch engines, this true-dual system replaces the restrictive factory exhaust from the crossmember back with a free-flowing, mandrel-bent design that helps your engine breathe the way it was meant to.
At the heart of the system is a pair of large cased Super 40 Series performance mufflers (muffler part #953048) fed by all mandrel-bent 3.00-inch aluminized steel tubing. A built-in H-pipe crossover assembly balances flow between the banks for maximum power and that deep, powerful tone the American Thunder series is known for. Every bend is smooth and full-diameter, keeping exhaust velocity high and backpressure low.
Key Benefits
This is a complete, ready-to-run kit that arrives with everything needed for a clean, factory-style fit. The 3.00-inch mandrel-bent tailpipes are custom bent to tuck up high above the rear end and exit with a slight turn down beneath the rear bumper, giving your classic A-Body an aggressive yet properly tucked appearance. U-bolt clamping and all necessary hardware and hangers are included, and the aggressive sound level makes your intentions clear the moment you fire it up.
- True-dual crossmember-back design with 3.00-inch inlet diameter
- All mandrel-bent 3.00-inch aluminized steel tubing for smooth, high-velocity flow
- Built-in H-pipe crossover assembly for balanced flow and added power
- Dual large cased Super 40 Series performance mufflers (PN 953048) included
- Custom-bent dual tailpipes that tuck high and exit with a turn-down under the rear bumper
- U-bolt clamping with all hardware and hangers included for installation
Material, Options & Warranty
Constructed from durable aluminized steel with a silver pipe finish, this system is backed by a 3-year Limited Warranty. If you’re after long-term corrosion resistance, the American Thunder system is also offered in stainless steel under part #817200, which carries a Lifetime Limited Warranty. Choose the construction that best matches your build and driving conditions. Note that exhaust tips are sold separately and no heat shield is included, giving you the freedom to finish the exit exactly how you want.
Fitment
This system is designed specifically for 2WD 1968-1972 GM A-Bodies with a V8 engine. It is CARB (California) compliant with an Emission Code of 5, making it a legal upgrade in emissions-restricted states. WARNING: This product carries a California Proposition 65 notice.
Whether you’re restoring a muscle-era A-Body or building a high-horsepower street machine, the American Thunder Crossmember-Back system pairs true-dual flow with a menacing, aggressive exhaust note for a performance upgrade you can hear and feel.
