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    • American Thunder Crossmember-Back Exhaust System Fits 1964-1966 Mustang, 2.50-Inch Stainless Steel System Aggressive To Moderate Sound Flowmaster
    • American Thunder Crossmember-Back Exhaust System Fits 1964-1966 Mustang, 2.50-Inch Stainless Steel System Aggressive To Moderate Sound Flowmaster
    • American Thunder Crossmember-Back Exhaust System Fits 1964-1966 Mustang, 2.50-Inch Stainless Steel System Aggressive To Moderate Sound Flowmaster
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    Sale!

    Flowmaster Flowmaster American Thunder Crossmember-Back Exhaust System 817273

    Vendor: Flowmaster
    Part Number: 817273
    Save $157
    Sale Price $1,249.95 Regular Price $1,406.95

    Available to order. In-stock orders typically ship in 1 to 2 business days.

    Not sure it fits your vehicle?
    Email sales@berryperformancesales.com with your year, make, model and engine, and we'll help you check fitment before you order.
    Fast Fulfillment: In-stock orders typically ship within 1 to 2 business days.
    Free Shipping on Orders Over $99 | Excludes freight shipments
    International Shipping Available: email sales@berryperformancesales.com for a quote.
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    This American Thunder® Crossmember-Back exhaust system is designed for all 1964-1966 Ford Mustang hardtop coupes with a V8 engine. The system features a free-flowing 2.50-inch mandrel-bent stainless steel H-pipe flowing into a pair of 40 Series Delta Flow® mufflers for maximum power and that deep iconic sound. The 2.50-inch mandrel-bent stainless tailpipes tuck up high and are finished off with a pair of long 2.50-inch 304 stainless steel tips for that show car look. Includes all necessary parts, hardware and easy to follow instructions and is covered by our Lifetime Limited Warranty. Note: Does Not fit GT models or convertibles.


    Flowmaster Flowmaster American Thunder Crossmember-Back Exhaust System 817273


    Specifications:

    Description_ABR SYS 64-66 MU
    Description_SHO SYS 64-66 MUSTANG V8
    Description_INV 64-66 MUSTANG V8 AMT 409S
    Description_ASC Does not fit GT or convertible models.
    Description_DES Flowmaster American Thunder Crossmember-Back Exhaust System
    Description_EXT Fits 1964-1966 Mustang, 2.50-inch stainless steel system. - Aggressive to moderate sound
    Description_MKT This American Thunder® Crossmember-Back exhaust system is designed for all 1964-1966 Ford Mustang hardtop coupes with a V8 engine. The system features a free-flowing 2.50-inch mandrel-bent stainless steel H-pipe flowing into a pair of 40 Series Delta Flow® mufflers for maximum power and that deep iconic sound. The 2.50-inch mandrel-bent stainless tailpipes tuck up high and are finished off with a pair of long 2.50-inch 304 stainless steel tips for that show car look. Includes all necessary parts, hardware and easy to follow instructions and is covered by our Lifetime Limited Warranty. Note: Does Not fit GT models or convertibles.
    Description_FAB Includes Hangers and Hardware for an Easy Installation
    Description_FAB Mandrel-bent 16-gauge Stainless Steel Tubing
    Description_FAB 40 Series Delta Flow Performance Mufflers
    Description_FAB Long Polished Stainless Steel Tips
    Description_FAB Includes Built-in "H" Balance Pipe
    Description_FAB Moderate Exterior Exhaust Tone
    Description_FAB Lifetime Limited Warranty
    Description_FAB Crossmember-Back System
    Description_ABR SYS 64-66 MU
    Description_SHO SYS 64-66 MUSTANG V8
    Description_INV 64-66 MUSTANG V8 AMT 409S
    Description_ASC Does not fit GT or convertible models.
    Description_DES Flowmaster American Thunder Crossmember-Back Exhaust System
    Description_EXT Fits 1964-1966 Mustang, 2.50-inch stainless steel system. - Aggressive to moderate sound
    Description_MKT This American Thunder® Crossmember-Back exhaust system is designed for all 1964-1966 Ford Mustang hardtop coupes with a V8 engine. The system features a free-flowing 2.50-inch mandrel-bent stainless steel H-pipe flowing into a pair of 40 Series Delta Flow® mufflers for maximum power and that deep iconic sound. The 2.50-inch mandrel-bent stainless tailpipes tuck up high and are finished off with a pair of long 2.50-inch 304 stainless steel tips for that show car look. Includes all necessary parts, hardware and easy to follow instructions and is covered by our Lifetime Limited Warranty. Note: Does Not fit GT models or convertibles.
    Description_FAB Includes Hangers and Hardware for an Easy Installation
    Description_FAB Mandrel-bent 16-gauge Stainless Steel Tubing
    Description_FAB 40 Series Delta Flow Performance Mufflers
    Description_FAB Long Polished Stainless Steel Tips
    Description_FAB Includes Built-in "H" Balance Pipe
    Description_FAB Moderate Exterior Exhaust Tone
    Description_FAB Lifetime Limited Warranty
    Description_FAB Crossmember-Back System
    Brand Flowmaster
    California Proposition 65 Yes
    California Proposition 65 Chemical Name Nickel (Metallic)
    California Proposition 65 Chemical Name Chromium (hexavalent compounds)
    CARB (California) Compliant Yes
    Catalytic Converter Included No
    2874 0
    Category Exhaust
    3728 Flat Band
    1882 Yes
    Emission Code 5
    Exhaust Series American Thunder
    11205 Silver
    9874 Welded
    9876 Angled
    1162 2.50
    9877 Slash Cut
    1163 Polished
    9881 No
    10104 29.125
    1164 304 Stainless Steel
    1161 2
    9878 No
    10980 Round
    9875 Single Wall
    9870 Dual Out Rear
    200 Natural
    353 No
    3390 Performance
    4364 Yes
    Heat Shield Included No
    Inlet Diameter 2.50
    596 Weld-On
    9871 2.50
    92 Yes
    11021 4.00
    11022 13.00
    11023 9.75
    11064 Chambered
    11048 4.00
    11049 13.00
    11050 9.75
    11073 Chambered
    9884 4.00
    1892 13.00
    4372 409 Stainless Steel
    4373 Oval
    9882 Black High-Temperature Paint Finish
    4367 No
    4368 No
    Muffler Included Yes
    9962 Slip-Fit
    4365 2.50
    4366 2.63
    9963 Slip-Fit
    4375 1
    Muffler Part Number Kit Only
    4374 2
    Muffler Series 40 Series Delta Flow
    1174 Chambered
    part type Exhaust System
    3530 409 Stainless Steel
    Product Type Exhaust System
    Sound Level Aggressive / Moderate
    4377 No
    Sub Category Exhaust and Tail Pipes
    4369 2.50
    4376 2
    Tail Pipe Quantity Dual
    4370 No
    Type Crossmember-back
    6014 No
    2126 Not Applicable
    Warning California Proposition 65
    Pipe Color Silver
    Drive 2WD
    9885 9.50
    Brand Flowmaster
    California Proposition 65 Yes
    California Proposition 65 Chemical Name Nickel (Metallic)
    California Proposition 65 Chemical Name Chromium (hexavalent compounds)
    CARB (California) Compliant Yes
    Catalytic Converter Included No
    2874 0
    Category Exhaust
    3728 Flat Band
    1882 Yes
    Emission Code 5
    Exhaust Series American Thunder
    11205 Silver
    9874 Welded
    9876 Angled
    1162 2.50
    9877 Slash Cut
    1163 Polished
    9881 No
    10104 29.125
    1164 304 Stainless Steel
    1161 2
    9878 No
    10980 Round
    9875 Single Wall
    9870 Dual Out Rear
    200 Natural
    353 No
    3390 Performance
    4364 Yes
    Heat Shield Included No
    Inlet Diameter 2.50
    596 Weld-On
    9871 2.50
    92 Yes
    11021 4.00
    11022 13.00
    11023 9.75
    11064 Chambered
    11048 4.00
    11049 13.00
    11050 9.75
    11073 Chambered
    9884 4.00
    1892 13.00
    4372 409 Stainless Steel
    4373 Oval
    9882 Black High-Temperature Paint Finish
    4367 No
    4368 No
    Muffler Included Yes
    9962 Slip-Fit
    4365 2.50
    4366 2.63
    9963 Slip-Fit
    4375 1
    Muffler Part Number Kit Only
    4374 2
    Muffler Series 40 Series Delta Flow
    1174 Chambered
    part type Exhaust System
    3530 409 Stainless Steel
    Product Type Exhaust System
    Sound Level Aggressive / Moderate
    4377 No
    Sub Category Exhaust and Tail Pipes
    4369 2.50
    4376 2
    Tail Pipe Quantity Dual
    4370 No
    Type Crossmember-back
    6014 No
    2126 Not Applicable
    Warning California Proposition 65
    Pipe Color Silver
    Drive 2WD
    9885 9.50


    This Part Fits:

    Year Make Model Submodel Notes
    1964 Ford Mustang Base
    1964 Ford Mustang Base
    1965 Ford Mustang Base
    1965 Ford Mustang Base
    1966 Ford Mustang Base
    Shipping Policy
    • Free shipping on orders over $99 (excludes freight shipments).
    • In-stock orders typically ship within 1 to 2 business days. Weekend and holiday orders are processed the next business day.
    • Orders ship from Defiance, Ohio and a nationwide network of warehouses and manufacturers.
    • Items showing an ETA are not in stock yet. ETAs come from the manufacturer and can change.
    • No P.O. Boxes. International orders need a shipping quote, so email us first.

    Read the full Shipping Policy

    Return Policy
    • 30-day return window from the ship date. Returns must be approved first; email sales@berryperformancesales.com with your order number.
    • Items must be unused, complete and in the original packaging.
    • A 20% restocking fee applies, and return shipping is paid by the buyer.
    • Not returnable: installed or modified parts, opened or used programmers and tuners, custom orders, Open Box, and Clearance or Final Sale items.
    • Damaged, defective or incorrect items must be reported within 48 hours of delivery with photos.

    Read the full Return Policy

    Disclaimer

    All products are sold for off-road use only unless otherwise specified. Buyer assumes all responsibility for installation and operation. Seller is not liable for any incidental, indirect, or consequential damages — including engine failure, labor costs, or vehicle downtime — resulting from the use of any product sold.

    By making a purchase from Berry Performance Sales, you acknowledge and agree to abide by the terms and conditions of these Policies.

    For any questions or concerns, please contact us — we’re always happy to help.

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