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Flowmaster - Header-back System 409S - Dual Rear or Side Exit - Moderate/Aggressive Sound (817654)

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$649.95

$722.95

You save: $73.00 (10%) off MSRP

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This part fits

  1. 1972 Chevrolet C10 Pickup Base
  2. 1972 Chevrolet C10 Pickup Base 5.0L V8 cid:307 cc:5031
  3. 1972 GMC C15/C1500 Pickup Base
  4. 1972 GMC C15/C1500 Pickup Base 5.0L V8 cid:307 cc:5031
  5. 1971 Chevrolet C10 Pickup Base
  6. 1971 Chevrolet C10 Pickup Base 5.0L V8 cid:307 cc:5031
  7. 1971 GMC C15/C1500 Pickup Base
  8. 1971 GMC C15/C1500 Pickup Base 5.0L V8 cid:307 cc:5031
  9. 1970 Chevrolet C10 Pickup Base 5.0L V8 cid:307 cc:5031
  10. 1970 GMC C15/C1500 Pickup Base
  11. 1970 GMC C15/C1500 Pickup Base 5.0L V8 cid:307 cc:5031
  12. 1970 Chevrolet C10 Pickup Base
  13. 1969 GMC C15/C1500 Pickup Base 5.0L V8 cid:307 cc:5031
  14. 1969 Chevrolet C10 Pickup Base
  15. 1969 Chevrolet C10 Pickup Base 5.0L V8 cid:307 cc:5031
  16. 1969 Chevrolet C10 Pickup Base 5.3L V8 cid:327 cc:5358
  17. 1969 GMC C15/C1500 Pickup Base
  18. 1968 Chevrolet C10 Pickup Base 5.0L V8 cid:307 cc:5031
  19. 1968 GMC C15/C1500 Pickup Base 5.3L V8 cid:327 cc:5358
  20. 1968 Chevrolet C10 Pickup Base 5.3L V8 cid:327 cc:5358
  21. 1968 GMC C15/C1500 Pickup Base 5.0L V8 cid:307 cc:5031
  22. 1967 Chevrolet C10 Pickup Base 4.6L V8 cid:283 cc:4638
  23. 1967 Chevrolet C10 Pickup Base 5.3L V8 cid:327 cc:5358
  24. 1967 GMC C15/C1500 Pickup Base 5.0L V6 cid:305 cc:5012
  25. 1967 GMC C15/C1500 Pickup Base 5.3L V8 cid:327 cc:5358
  26. show all...
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About this product

Part #: 817654

Flowmaster's American Thunder crossmember-back exhaust system for the 1967 - 1972 GM C10/C15 1/2 ton 2WD (Coil Spring) pickup truck is perfect for the person looking for moderate to aggressive sound levels with all of the performance benefits that you would expect from Flowmaster. This crossmember-back DOR/DOS (Dual Out Rear, Dual Out Side) system features dual Super 44 Series mufflers, 2.50 in. mandrel bent 409S stainless steel tubing and all the hardware necessary for a great fitting installation. (Stainless tips sold separately). This system is routed in a fashion that accommodates both long and short wheelbases with automatic or manual transmissions, and provides adequate clearance for substantially lowered vehicles. The exhaust system is covered by Flowmaster's Lifetime Limited Warranty.

More Details

Exhaust SeriesAmerican Thunder
Exhaust TypeDual
Exit PositionDual Out Side
Exit PositionDual Out Rear
Exit StyleStraight
Heat Shield AttachedNo
Inlet Diameter2.500 in.
Inlet Inside Diameter2.500 in.
MaterialStainless Steel
Muffler Count2
Muffler Part NumberKit Only
Muffler SeriesSuper 44 Series
Outlet Diameter2.500 in.
Outlet Outside Diameter2.500 in.
Single or DualDual
Sound LevelModerate/Aggressive
System TypeHeader Back
Tail Pipe Diameter2.500 in.
Tip Quantity0
TitleFlowmaster 817654 Crossmember back 409S - Dual Rear or Side Exit - Moderate/Aggressive Sound
Tubing Diameter2.500 in.
Additional Documents
  1. Certificate of Originpdf
  2. Installation Instructionspdf
  3. Warrantypdf

See what our community says about flowmaster products

product page reviews icon 0product page reviews icon 1product page reviews icon 2product page reviews icon 3product page reviews icon 4
What made you choose this particular product?
I wanted my muscle car to sound like a muscle car.
Is this your first time buying from this brand? Did you consider other brands?
I previously ordered a Dynomax exhaust and waited 4 months, however it was out of stock.
Was it easy to install? Any installation tips that will help others?
Hatch tire and Auto installed it.
Once you've had a chance to use the product, did it meet your expectations?
I just had it installed. There is a bit more drone, but that is to be expected if you want that deeper tone.
View on DANIEL's build
Cole Perkins

20

Cole Perkins
2004 Ford Ranger
product page reviews icon 0product page reviews icon 1product page reviews icon 2product page reviews icon 3product page reviews icon 4
What made you choose this particular product?
Good sound
View on Cole's build
product page reviews icon 0product page reviews icon 1product page reviews icon 2product page reviews icon 3product page reviews icon 4
What made you choose this particular product?
Crackle's and pops in certain rpm, doesn't sound raspy either
Is this your first time buying from this brand? Did you consider other brands?
First time
Was it easy to install? Any installation tips that will help others?
Professionally installed
Once you've had a chance to use the product, did it meet your expectations?
Yes
View on Jonathan's build
product page reviews icon 0product page reviews icon 1product page reviews icon 2product page reviews icon 3product page reviews icon 4
Was it easy to install? Any installation tips that will help others?
Easy to install, just get a better pair of exhaust hangers.
View on Evan's build
product page reviews icon 0product page reviews icon 1product page reviews icon 2product page reviews icon 3product page reviews icon 4
What made you choose this particular product?
Researched how it would sound on my truck
Is this your first time buying from this brand? Did you consider other brands?
Yes my first time, and I did consider other brands but decided on Flowmaster
Once you've had a chance to use the product, did it meet your expectations?
It was a great choice and my truck sounds 100 times better than the cherry bomb
View on Jon's build

TOP RATED Flowmaster Exhaust

California prop 65 warningWARNING: Cancer and Reproductive Harm www.p65warnings.cs.gov

*Some manufacturer restrictions apply.

About Flowmaster

Manufacturer of performance exhaust systems, mufflers, cold air intakes, turbo boost modules, catalytic converters, race mufflers, headers and numerous exhaust accessories for late model cars, trucks, off-road, Jeeps, SUV’s, classic muscle cars, powersports vehicles and more. Flowmaster® gives you lots of exhaust choices with 12 designs of chambered mufflers, 3 styles of our exclusive “laminar-flow” mufflers and a new line of FlowFX “straight-through” performance mufflers, along with 5 sound categories of exhaust systems, giving you the customer, the power to custom tailor the sound of your vehicle whether you prefer mild, moderate or aggressive tones and sound levels.

Benefits of adding this mod

An upgraded exhaust system is one of the easiest modifications that offers an immediate, noticeable performance improvement. Whether you’re cruising an M3 or modding a diesel truck, an upgraded exhaust will open up the restrictive factory system, allowing your engine to breathe better and deliver peak power! From lighter weight exhaust headers to improved cat-back systems, to better sounding mufflers, modifying your exhaust setup is a great place to express the character of your ride in a unique and cost effective way. Whatever you’re looking for in a modified exhaust system, we can provide the absolute best systems to make your vision a reality.

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we ship worldwide!

Based in California with 3 warehouses across the country, we’re sending out shipments everyday of the week, even Saturdays. Because your next mod shouldn’t have to wait.

+ FREE GROUND SHIPPING ON U.S. ORDERS OVER $99
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Wheelwell helps you organize all your stuff for your car, I’ve loaded all my cars on Wheelwell and you can see all the parts I’ve put in them and that may help you make a decision with your own build.

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Matt Farah

Smoking Tire / The Drive

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Thank you for all the help, really. You guys are awesome. This is all great info and I really appreciate everything you have done to help me with my build.

James M.

Ford Focus ST

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Your customer service is wonderful. Thank you for taking care of this. My review will express all. Thank you!

Wallace R

Chevrolet Silverado 1500