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

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$682.95

$759.00

You save: $76.05 (10%) off MSRP

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This part fits

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

Sam Jacobson

550

Sam Jacobson
2013 Dodge Dart
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What made you choose this particular product?
I wanted a little more rumble from the car at idle.
What were you trying to accomplish by adding this product?
Have more idle, replaced the Flowmaster dBX muffler for the HP-2 Shorty.
Once you’ve had a chance to use the product, did it meet your expectations?
With resonated tips added at the same time, I have enjoyed the sound of my exhaust more than I ever have! When the car is cold my car's exhaust pops louder than ever and I love it! It is a muffler rated way higher on the Flowmaster exhaust chart!
View on Sam's build
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What made you choose this particular product?
Performance and sound
What were you trying to accomplish by adding this product?
Power and sound
Once you’ve had a chance to use the product, did it meet your expectations?
Very happy with it. Car is very loud but with a nice deep tone.
View on Dakota'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?
the sound
What were you trying to accomplish by adding this product?
get rid of the crap mufflers on my pypes exhaust
View on Jacob'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?
My brother had it installed for my birthday.
What were you trying to accomplish by adding this product?
More horsepower and opening up the exhaust more.
Was it easy install? Any installation tips that will help others?
I had D&W Tire install it for me. They did a great job with reworking the exhaust for me.
Once you’ve had a chance to use the product, did it meet your expectations?
Good price for labor and parts. Made my little truck sound really good.
Any additional comments?
Nope
View on Aaron'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?
Good sound, not much performance increase
What were you trying to accomplish by adding this product?
Added a much better sound than stock, but could be louder
Was it easy install? Any installation tips that will help others?
Required welds, had to outsource
View on Jon's build
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.

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