

Flowmaster 17742 Header-back 409S - American Thunder Kit - DOR/S - Mod/Agg Sound
Key item features
- Sound Profile: Features Super 44 Series mufflers, delivering a deep, powerful sound with a moderate to aggressive exterior exhaust tone.
- Durable Construction: Constructed from mandrel-bent 16-gauge aluminized steel tubing for lasting performance.
- Complete System: A cross-member back true dual exhaust system with an H-pipe crossover for maximum power.
- Vehicle Compatibility: Designed for 1973-1974 Chevrolet and GMC C10, C20 2wd trucks with V8 engines.
- Installation Inclusions: Includes all necessary hangers and hardware for a complete installation.
- Tailpipe Options: Offers choices for dual out rear under the bumper or dual out the sides behind the rear tires.
- Design Adaptability: Accommodates both long and short wheelbases, automatic or manual transmissions, and lowered vehicles.
Specs
- Vehicle makeChevrolet
- Vehicle model17742
- Vehicle year1973, 1974
- Inlet diameter2.50
- Outlet diameter2.50
- Muffler typePerformance Mufflers
- Free shipping
Free 30-day returns
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Compare with similar items
| Product | Viewing this itemFlowmaster 17742 Header-back 409S - American Thunder Kit - DOR/S - Mod/Agg Sound ![]() Now $903.02 current price Now $903.02, Was $999.95$999.95 23 out of 5 Stars. 2 reviews | Flowmaster Signature Series Exhaust System ![]() $1,058.63 current price $1,058.63 | Flowmaster 1050-FM Flowmaster Header-back Exhaust System ![]() $599.95 current price $599.95 | Flowmaster 817174 Header-back System 409S - Dual Rear Exit - American Thunder -Moderate/Aggressive ![]() $1,177.95 current price $1,177.95 | Flowmaster Signature Series Exhaust System ![]() $916.37 current price $916.37 | Flowmaster Signature Series Exhaust System ![]() Now $888.52 current price Now $888.52, Was $966.60$966.60 | Flowmaster Signature Series Exhaust System ![]() $737.15 current price $737.15 | Flowmaster 817795 Outlaw Exhaust System Kit ![]() $1,024.95 current price $1,024.9514 out of 5 Stars. 1 reviews | Flowmaster 17120 Header-back System - Dual Side Exit - American Thunder - Moderate/Aggressive ![]() $1,024.95 current price $1,024.9515 out of 5 Stars. 1 reviews | Flowmaster 17201 Header-back System - Dual Rear Exit - American Thunder - Aggressive Sound ![]() Now $877.88 current price Now $877.88, Was $999.95$999.95 |
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| Vehicle make | ChevroletFlowmaster 17742 Header-back 409S - American Thunder Kit - DOR/S - Mod/Agg Sound | RamFlowmaster Signature Series Exhaust System | -Flowmaster 1050-FM Flowmaster Header-back Exhaust System | -Flowmaster 817174 Header-back System 409S - Dual Rear Exit - American Thunder -Moderate/Aggressive | FordFlowmaster Signature Series Exhaust System | Chevrolet; GMCFlowmaster Signature Series Exhaust System | ToyotaFlowmaster Signature Series Exhaust System | FordFlowmaster 817795 Outlaw Exhaust System Kit | ChevroletFlowmaster 17120 Header-back System - Dual Side Exit - American Thunder - Moderate/Aggressive | -Flowmaster 17201 Header-back System - Dual Rear Exit - American Thunder - Aggressive Sound |
|---|---|---|---|---|---|---|---|---|---|---|
| Vehicle model | 17742Flowmaster 17742 Header-back 409S - American Thunder Kit - DOR/S - Mod/Agg Sound | 1500Flowmaster Signature Series Exhaust System | CamaroFlowmaster 1050-FM Flowmaster Header-back Exhaust System | 817174Flowmaster 817174 Header-back System 409S - Dual Rear Exit - American Thunder -Moderate/Aggressive | F-150Flowmaster Signature Series Exhaust System | -Flowmaster Signature Series Exhaust System | TacomaFlowmaster Signature Series Exhaust System | FocusFlowmaster 817795 Outlaw Exhaust System Kit | El CaminoFlowmaster 17120 Header-back System - Dual Side Exit - American Thunder - Moderate/Aggressive | CamaroFlowmaster 17201 Header-back System - Dual Rear Exit - American Thunder - Aggressive Sound |
| Vehicle year | 1973Flowmaster 17742 Header-back 409S - American Thunder Kit - DOR/S - Mod/Agg Sound | 2019Flowmaster Signature Series Exhaust System | 1967Flowmaster 1050-FM Flowmaster Header-back Exhaust System | 1955Flowmaster 817174 Header-back System 409S - Dual Rear Exit - American Thunder -Moderate/Aggressive | 2021Flowmaster Signature Series Exhaust System | 2019Flowmaster Signature Series Exhaust System | 2016Flowmaster Signature Series Exhaust System | -Flowmaster 817795 Outlaw Exhaust System Kit | 1964Flowmaster 17120 Header-back System - Dual Side Exit - American Thunder - Moderate/Aggressive | 1967Flowmaster 17201 Header-back System - Dual Rear Exit - American Thunder - Aggressive Sound |
| Inlet diameter | 2.50Flowmaster 17742 Header-back 409S - American Thunder Kit - DOR/S - Mod/Agg Sound | 3.00 inFlowmaster Signature Series Exhaust System | 3.00 inFlowmaster 1050-FM Flowmaster Header-back Exhaust System | 2.50Flowmaster 817174 Header-back System 409S - Dual Rear Exit - American Thunder -Moderate/Aggressive | -Flowmaster Signature Series Exhaust System | 3.00 inFlowmaster Signature Series Exhaust System | -Flowmaster Signature Series Exhaust System | 3.00 inFlowmaster 817795 Outlaw Exhaust System Kit | 2.5 inFlowmaster 17120 Header-back System - Dual Side Exit - American Thunder - Moderate/Aggressive | 3.00 inFlowmaster 17201 Header-back System - Dual Rear Exit - American Thunder - Aggressive Sound |
About this item
Product details
This American Thunder exhaust system was specially designed for 1973-1974 Chevrolet and GMC C10 and C15 1/2 ton and 3/4 ton 2wd trucks and is perfect for the person looking for moderate to aggressive interior and exterior sound levels. The system is a cross-member back exhaust complete with a built-in H-pipe crossover, all mandrel-bent 2.50 in. aluminized steel tubing, a pair of Super 44 Series performance mufflers and your choice of tailpipe exits. Either dual out rear under the bumper for a muscular look or dual out the sides behind the rear tires for that classic truck look. The system includes all hardware necessary for installation and is designed to accommodate both long and short wheelbases, with either an automatic or manual transmission and provides adequate clearance for substantially lowered vehicles. The exhaust system is covered by our 3-year Limited Warranty. Notes: Does Not include exhaust tips or header reducer cones. This system is not emissions compliant on vehicles that were originally equipped with catalytic converters.;
- Super 44 Series Mufflers for Deep Powerful Sound
- Mandrel-bent 16-gauge Aluminized Steel Tubing
- Includes Hangers and Hardware for Installation
- Moderate to Aggressive Exterior Exhaust Tone
- Cross member back True Dual Exhaust System
- H-pipe Crossover for Maximum Power
- Does Not Include Header Reducers
Specifications
Vehicle make
Vehicle model
Vehicle year
Inlet diameter
Warranty
Warranty information
Please be aware that the warranty terms on items offered for sale by third party Marketplace sellers may differ from those displayed in this section (if any). To confirm warranty terms on an item offered for sale by a third party Marketplace seller, please use the 'Contact seller' feature on the third party Marketplace seller's information page and request the item's warranty terms prior to purchase.
Warnings
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Customer ratings & reviews
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Showing 1-2 of 2 reviews
I just installed this kit on my '75 crew cab dually w/ 454 and Hedman headers . It did require me to extend the tubing about 3 ft on each side to reach the headers but that was expected. I ended up welding everything together and only clamping the tailpipes to the mufflers. Sounds pretty good, would recommend.
Good kit bad match with jegs headers
These headers were sold in a kit with thunder headers Flowmaster exhaust system. Issue 1. The collector and the front pipe are the same size. Issue 2. Header collector outlet inline with front cross member exhaust kit only had one pipe bent to fit around the front cross member. Issue 3. If your truck has a trailer hitch the rear of the exhaust and tail pipes will be all over it. If your going to attempt this kit at home on the ground look for something better. This was a perfect example of no one knowing what they were doing when they paired this kit up.
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