Description
Overview
The Flowmaster American Thunder Crossmember-Back Exhaust System is purpose-built to bring modern flow and unmistakable attitude to 1967-1972 Chevrolet and GMC C10 and C15 1/2-ton 2WD trucks equipped with coil spring suspension. Engineered from the crossmember back, this complete kit replaces tired factory plumbing with a mandrel-bent, high-flow design that helps your classic truck breathe better while delivering a rich, muscular exhaust note. It’s the ideal upgrade for the enthusiast who wants a moderate to aggressive sound level inside the cab and out.
At the heart of the system sits a pair of Super 44 Series performance mufflers, tuned for that signature deep, aggressive tone Flowmaster is known for. A built-in H-pipe crossover balances flow between banks for smoother performance and a fuller sound, while all mandrel-bent 2.50-inch stainless steel tubing keeps exhaust velocity strong and resists corrosion for the long haul.
Key Benefits
- Mandrel-bent 2.50-inch stainless steel tubing for maximum flow and lasting durability
- Dual Super 44 Series performance mufflers for an aggressive, moderate-to-loud tone
- Built-in H-pipe crossover for balanced flow and a fuller exhaust note
- Complete crossmember-back kit with all hardware necessary for installation
- Generous clearance designed to work even on substantially lowered trucks
- Covered by Flowmaster’s Lifetime Limited Warranty and CARB (California) compliant
Choose Your Tailpipe Exit
This American Thunder system gives you four distinct tailpipe configurations so you can dial in the look that suits your build. Select a set slightly angled down to clear larger rear bumpers, a straight-out-the-back layout that exits under the rear bumper, a side-exit arrangement behind the rear tires for that classic truck stance, or a dump-style exit behind the rear tires level with the body. Whichever route you choose, the dual tailpipe design finishes the aggressive character of the setup. Note that exhaust tips are sold separately and no heat shield is included, giving you the freedom to customize the finishing touches.
Fitment
Designed specifically for 1967-1972 Chevrolet and GMC C10 and C15 1/2-ton 2WD trucks with coil spring suspension, this system fits both short and long wheelbase trucks. The silver-finish, stainless steel construction and CARB-compliant design make it a smart, road-legal upgrade for your vintage hauler.
For those who prefer aluminized steel construction instead of stainless, Flowmaster also offers system #17654, which carries a 3-year Limited Warranty. The stainless American Thunder system detailed here remains the premium choice, backed by the Lifetime Limited Warranty for confidence that lasts as long as your truck stays on the road. From the built-in crossover to the choice of exits, every detail is engineered to make your classic C10 or C15 sound and perform like it means business.
