Doug Thorley Headers® - Steel 3/4 Length 4-1 Exhaust Headers with Adapters

0 reviews|Item # 372848957
$598.00 - $652.00
In Stock (8) - Ships Tomorrow 01.21.19
1974 Chevy Monte Carlo
Fits Following Model(s):
  • with Small Block Engine
    Fits With Straight or Angle Plug Heads.
  • This is a CARB compliant part, legal for use on vehicles built to meet CARB standards and/or registered in California and other states which follow CARB standards (CARB EO: D-540-5).
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    Product Details

    Chevy Monte Carlo with Small Block Engine 1974, Steel 3/4 Length 4-1 Exhaust Headers with Adapters by Doug Thorley Headers®. Collector Outlet Diameter: 3". Are you tired of dragging your long tube headers on the ground every time your lowered car hits a bump? If so, then these headers are for you! Just a little shorter than true long tube headers, Doug's designed these to give you the maximum in performance while keeping them short enough to not smack the ground when the road gets a little bumpy. Of course the shorter design makes for a bit easier of an install than long tubes also, you definitely don't need to be lowered to run these. To make these headers last, Doug's made them out of industry leading 14-gauge tubing with 3/8" thick flanges. Doug's headers come beautifully ceramic coated to greatly reduce surface temperatures and protect them from the environment. All 100% American made, and backed by Doug's lifetime warranty. Install these headers today and feel your vehicle's true power potential!

    Notes: This is a CARB compliant part, legal for use on vehicles built to meet CARB standards and/or registered in California and other states which follow CARB standards (CARB EO: D-540-5).

    Fitment notes: Fits With Straight or Angle Plug Heads.

    Doug Thorley Headers


    Header Material: Steel
    Collector Diameter: 3"
    Header Style: 3/4 Length 4:1 Header
    Material: Steel
    Finish: Silver Ceramic Coated
    Primary Tube Diameter: 1-5/8"
    Primary Tube Gauge: 14 Gauge
    Collector Attachment: 3-bolt Flange
    Tuned: No
    Flange Thickness: 3/8"
    Bolts and/or Studs Included: Yes
    Gaskets Included: Yes
    Reducers/Adapters Included: Yes
    Y-Pipe (Crossover) Included: No
    Weld Up: Adapters must be welded to exhaust system
    Quantity: Sold as a Pair
    Warranty: Limited Lifetime to original purchaser


    • Driven by a passion for performance and superior quality
    • Designed to maximize horsepower and torque of your vehicle
    • Made with meticulous attention to detail and unmatched craftsmanship

    Doug's Long Tube Headers replace restrictive stock exhaust manifolds with long primary tubes designed to dramatically increase the flow of exhaust gasses, and reduce power robbing back pressure within the exhaust system. Allowing the engine to breathe more freely improves power and efficiency, making Doug's Long Tube Headers one of the most cost-effective modifications you can make to your vehicle.

    The Long Tube Header is perfect for any high performance street or strip application. Each header is constructed from thick wall steel, and all come finished with Doug's beautiful ceramic coating for long-lasting performance.

    For over 50 years, Doug Thorley Headers has been an innovator in the automotive aftermarket. Driven by a passion for performance and superior quality, they are committed to developing 100% American-made products that will reliably deliver maximum horsepower and torque. Doug Thorley Headers® has been pushing the limits of automotive technology since they first invented the Tri-Y header in 1958, and they do it all on American soil.

    California Residents

    CARB To confirm your vehicle's CARB certification, please enter EO number at


    Doug Thorley Headers

    Limited Lifetime Warranty

    Unless otherwise specified, Doug Thorley Headers (hereinafter DTH) header products are warranted against defective materials and workmanship for as long as you, the original consumer purchaser, owns said header product. DTH exhaust products, defined as any component “downstream” of a DTH header product or OE factory exhaust manifolds, are warranted against defective materials and workmanship for a period of 5 years from the original consumer purchase date. These limited warranties are offered solely to the original purchaser, are non-transferrable and proof of purchase is required for any warranty claims. These warranties shall be limited to the repair, adjustment, and/or replacement of defective parts at the discretion of DTH. Authorized product(s) returned will be repaired or replaced also at the discretion of DTH. All warranties become void if any product shows evidence of any modification done without the express consent of DTH, and includes mishandling, bending, welding, mutilation of parts, and insulating wrap products. Nor shall DTH be responsible for any damages, whether consequential, special, contingent or otherwise; or expenses or injury that may arise from the use of DTH products. The bluing and discoloration of chrome exhaust products is considered normal, as is the dulling of ceramic coated products, and as such, coatings are not covered under the terms of the warranty. Environmental exposure and rust apparent during the extended life of products is also considered normal and excluded from the warranty. Any DTH product that has been discontinued from new sales for a period of 5 years or longer will no longer be eligible for replacement under terms of the warranty, the repair of any defective parts will be the only option. This warranty policy supersedes any other warranties offered by DTH. DTH reserves the right to modify the warranty policy at any time, and a detailed copy of sale terms, condition and warranty information is available upon request.

    Magnuson-Moss Warranty Act:
    Legally, a vehicle manufacturer cannot void the warranty on a vehicle due to an aftermarket part unless they can prove that the aftermarket part caused or contributed to the failure in the vehicle (per the Magnuson Moss Warranty Act (15 U.S.C. 2302(C)) Learn More
    Low Prices Price match guarantee
    Guaranteed Fitment Always the correct part
    In-House Experts We know our products
    Easy Returns Quick & Hassle Free

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