• The Flowmaster 40 Series Muffler takes the checkered flag as Flowmaster's most aggressive-sounding muffler
• Quality Flowmaster muffler crafting uses aluminized steel for corrosion resistance and precise mig welds for maximum durability
• The Flowmaster 40 Series is highly recommended for early muscle cars, off-road and race vehicles and dual-exhaust rides
• Hear the power of your engine with the excellent interior resonance of the 40 Series—especially at 1800-2000 RPMs and again at 2400-2600 RPMs
• Original two-chamber design maximizes horsepower and torque
• The centerpiece muffler for many Flowmaster American Thunder Exhaust Systems
• Casing embossed with the Flowmaster name
• Your Flowmaster 40 Series Muffler carries a 3-year warranty

Get the original aggressive Flowmaster sound that puts serious punch into your vehicle's presence and power. The Flowmaster 40 Series Muffler maximizes horsepower, torque and flow with its two-chamber design—the original two-chamber Flowmaster muffler.

If the roaring sound of an engine is music to your ears, you'll love the Flowmaster 40 Series. Aggressive sound is maximized outside, while high-volume interior resonance lets you hear every push of the pedal. It's this total sound design that makes the Flowmaster 40 Series the centerpiece of many of Flowmaster's outstanding American Thunder Exhaust Systems.

Ideal for early muscle cars, off-road rides and dual exhaust cruisers, the Flowmaster 40 Series boasts the quality construction you'd expect from Flowmaster. Each Flowmaster Muffler is built with 16-gauge aluminized steel for corrosion resistance and fully mig-welded for maximum durability. Best yet, your Flowmaster 40 Series Muffler boasts a 3-year warranty.

Flowmaster 40 Series American Thunder Mufflers come in a variety of inlet/outlet configurations and sizes, shown above. Select the inlet/outlet diameter you need from the drop down at right.

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40 Series American Thunder Standard Muffler Get the original aggressive Flowmaster sound that puts serious punch into your vehicle's presence and power. The Flowmaster 40 Series Muffler maximizes horsepower, torque and flow with its two-chamber design—the original two-chamber Flowmaster muffler. If the roaring sound of an engine is music to From: $72.93