Check the listing for details. 17224 Flowmaster American Thunder Cat-back Exhaust System. Condition: New, Made in US. Listed at 562.95 USD. Fits 1996-1999 Chevrolet Silverado, GMC Sierra 2500/3500 5.7L HD or 7.4L engine. - Moderate sound. This Flowmaster American Thunder® cat-back exhaust system is custom designed for 1996-1999 Chevrolet Silverado and GMC Sierra 2500/3500 trucks with the 5.7L and 7.4L engine is perfect for the person looking for a moderate sound level inside and outside of the truck, with all of the performance benefits that expect from Flowmaster®. This bolt-on emissions-legal system features a dual 3.00-inch inlet 50 Series Big Block™ muffler for a deep powerful tone and includes an aluminum heat shield and stainless steel clamps. The single 3.00-inch aluminized steel mandrel-bent tailpipe uses the factory hanger locations and is finished off with a turndown style tip that exits behind the right rear wheel.