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Flowmaster American Thunder Cat-back Exhaust System

Part # 817328 Be the first to write a review

2001-2006 (2007 Classic) Chevrolet Silverado, GMC Sierra 2500HD/3500HD with 6.0L or 8.1L engine with dual inlet muffler. Stainless Steel. - Aggressive sound

Flowmaster American Thunder Cat-back Exhaust System

Estimated Ship Date: 07/31/2026
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Advertised Price $849.95
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Emissions

This part is legal for sale or use on Emissions Controlled Vehicles, Uncontrolled (Non-Emissions Controlled) Vehicles, and Racing Use Only Vehicles because it does not affect vehicle emissions and is not covered by emissions regulations.

See Emissions Details
For the person who wants a subtle custom appearance with all the benefits that a Flowmaster Cat-back exhaust system provides. This American Thunder system for the 2001-2006 (2007 Classic) Chevrolet Silverado, GMC Sierra 2500HD/3500HD with 6.0L or 8.1L engine with dual inlet muffler, delivers a moderate interior tone with a deep powerful exterior tone and is suited to the enthusiast who wants their performance to be heard. The system attaches to the back of the catalytic converter with a dual inlet 50 Series Big Block muffler for a deep powerful sound without being obnoxious. Includes a large custom formed aluminum heat shield with stainless clamps and easily attaches directly to the muffler body. The custom bent 3.50-inch 409 stainless steel tailpipe uses the factory hanger locations for an easy installation and exits out behind the right side rear wheel which is ideal for towing. The tailpipe is finished off with a large 4.00-inch polished 304 stainless steel tip embossed with the Flowmaster logo. Like all Flowmaster systems, the benefits include improved throttle response, power and mileage. Designed for an easy fit, these systems include all necessary parts, hardware and easy to follow instructions for a trouble free installation. Covered by Flowmaster's Lifetime Limited Warranty.

Features:

  • 3.50-inch Mandrel-bent 16-gauge Stainless Steel Tubing
  • Includes Hangers and Hardware for an Easy Installation
  • Large 4.00-inch Polished 304 Stainless Steel Tip
  • Moderately Aggressive Exterior Exhaust Tone
  • Connects After Factory Catalytic Converter
  • Uses the Factory Hanger Locations
  • Quick and Easy Installation
  • Lifetime Limited Warranty

About Flowmaster

Shop the complete line of Flowmaster products for exhaust systems, mufflers, and more that deliver the iconic Flowmaster sound. Available at Holley.com!

Brand Flowmaster
California Proposition 65Yes
CARB (California) CompliantYes
Catalytic Converter IncludedNo
Catalytic Converter Quantity0
CategoryExhaust
Clamping TypeFlat Band
Clamps IncludedYes
Drive2WD
4WD
Emission Code5
Exhaust SeriesAmerican Thunder
Exhaust Tip ColorSilver
Exhaust Tip ConnectionWelded
Exhaust Tip CutAngled
Exhaust Tip Diameter4.00 IN
Exhaust Tip EdgeRolled Edge Angle Cut
Exhaust Tip FinishPolished
Exhaust Tip IntercooledNo
Exhaust Tip Length10.00 IN
Exhaust Tip Material304 Stainless Steel
Exhaust Tip Quantity1
Exhaust Tip ResonatedNo
Exhaust Tip ShapeRound
Exhaust Tip WallSingle Wall
Exit StyleSingle Out Side
FinishNatural
Gasket Or Seal IncludedNo
Grade TypePerformance
Hangers IncludedYes
Heat Shield IncludedNo
Inlet Diameter3.00 IN
Inlet TypeClamp-On
Main Piping Diameter3.50 IN
Mounting Bracket IncludedNo
Muffler Body Height5.00 IN
Muffler Body Length22.00 IN
Muffler Body Material409 Stainless Steel
Muffler Body ShapeOval
Muffler Body Width12.00 IN
Muffler FinishBlack High-Temperature Paint Finish
Muffler Flanged InletNo
Muffler Flanged OutletNo
Muffler IncludedYes
Muffler Inlet ConnectionSlip-Fit
Muffler Inlet Inside Diameter3.00 IN
Muffler Inlet LocationDual
Muffler Inlet Outside Diameter3.13 IN
Muffler Outlet ConnectionSlip-Fit
Muffler Outlet Quantity1
Muffler Part NumberKit Only
Muffler Quantity1
Muffler Series50 Series Big Block
Muffler TypeChambered
Part TypeExhaust System
Pipe ColorSilver
Pipe Material409 Stainless Steel
Product TypeExhaust System
Sound LevelAggressive
Spring Bolt Kit IncludedNo
Sub CategoryExhaust and Tail Pipes
Tail Pipe Outlet Outside Diameter3.50 IN
Tail Pipe Quantity1
Single
Tail Pipe Tapered OutletNo
TypeCat-Back
Valve IncludedNo
Valve TypeNot Applicable
UPC700042024506
California Proposition 65 Chemical NameChromium (hexavalent compounds)
Nickel (Metallic)
Part Number817328
5

This part is legal for sale or use on Emissions Controlled Vehicles, Uncontrolled (Non-Emissions Controlled) Vehicles, and Racing Use Only Vehicles because it does not affect vehicle emissions and is not covered by emissions regulations.
Fits 2001-2006 (2007 Classic) Chevrolet Silverado and GMC Sierra 2500 3/4 Ton and 1 Ton HD truck with 6.0L or 8.1L engine with dual inlet muffler, fits 2/4 wheel drive models with extended cab or crew cab.
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    Some parts are not legal for use in California or other states with similar regulations.