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Kenworth W900A Exhaust Parts

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  • Qty in Cart
  • Quantity
  • Price
  • Subtotal
  • BESTfit Chrome Exhaust Adapter Reducer 6 OD X 5 ID X 8 Inch

    BESTfit Chrome Exhaust Adapter Reducer 6 OD X 5 ID X 8 Inch

    BESTFIT TRUCK PARTS

    $106.99
    BESTfit 6 To 5 Inch O.D.-I.D. X 8 Inch OAL Chrome-Plated Steel Reducer PipeDoes your exhaust build have different size pipes? 4 State Trucks offers this high quality reducer that allows pipes of...
    09-080100169
    SKU:
    09-080100169
    Diameter Options:
    6 Inch
    Truck Class:
    Universal
    Length Options:
    8 Inch
    Material Options:
    Steel
    Make:
    Universal Items
    Finish Options:
    Chrome-Plated
    Product Type:
    Exhaust
    $106.99
    Qty in Cart: 0
    Price:
    $106.99
    Subtotal:
  • BESTfit Aluminized Exhaust Adapter Reducer 6 OD X 5 ID X 8 Inch

    BESTfit Aluminized Exhaust Adapter Reducer 6 OD X 5 ID X 8 Inch

    BESTFIT TRUCK PARTS

    $45.59
    BESTfit 6 To 5 Inch O.D.-I.D. X 8 Inch OAL Aluminized Steel Reducer PipeAre you building a custom exhaust that requires different pipe sizes? 4 State Trucks offers this high quality reducer that is...
    09-080100168
    SKU:
    09-080100168
    Diameter Options:
    6 Inch
    Truck Class:
    Universal
    Length Options:
    8 Inch
    Material Options:
    Aluminized Steel
    Make:
    Universal Items
    Product Type:
    Exhaust
    Ready To Ship:
    Yes
    $45.59
    Qty in Cart: 0
    Price:
    $45.59
    Subtotal:
  • BESTfit Aluminized Exhaust Adapter Reducer 6 OD X 4 OD X 8 Inch

    BESTfit Aluminized Exhaust Adapter Reducer 6 OD X 4 OD X 8 Inch

    BESTFIT TRUCK PARTS

    $53.99
    BESTfit 6 To 4 Inch O.D.-O.D. X 8 Inch OAL Aluminized Steel Reducer Pipehigh quality reducer that is made to smoothly connect pipes of different size on your exhaust. It is constructed with a premium...
    09-080100167
    SKU:
    09-080100167
    Truck Class:
    Universal
    Diameter Options:
    6 Inch
    Length Options:
    8 Inch
    Material Options:
    Aluminized Steel
    Make:
    Universal Items
    Product Type:
    Exhaust
    $53.99
    Qty in Cart: 0
    Price:
    $53.99
    Subtotal:
  • BESTfit Chrome Exhaust Adapter Reducer 6 ID X 5 OD X 8 Inch

    BESTfit Chrome Exhaust Adapter Reducer 6 ID X 5 OD X 8 Inch

    BESTFIT TRUCK PARTS

    $106.99
    BESTfit 6 To 5 Inch I.D.-O.D. X 8 Inch OAL Chrome-Plated Steel Reducer PipeIf you are looking to connect two different sized exhaust pipes, 4 State Trucks offers this high quality reducer that keeps...
    09-080100166
    SKU:
    09-080100166
    Truck Class:
    Universal
    Diameter Options:
    6 Inch
    Length Options:
    8 Inch
    Material Options:
    Steel
    Make:
    Universal Items
    Finish Options:
    Chrome-Plated
    Product Type:
    Exhaust
    Ready To Ship:
    Yes
    $106.99
    Qty in Cart: 0
    Price:
    $106.99
    Subtotal:
  • BESTfit Aluminized Exhaust Adapter Reducer 6 ID X 5 ID X 8 Inch

    BESTfit Aluminized Exhaust Adapter Reducer 6 ID X 5 ID X 8 Inch

    BESTFIT TRUCK PARTS

    $45.59
    BESTfit 6 To 5 Inch I.D.-I.D. X 8 Inch OAL Aluminized Steel Reducer PipeDo you have an exhaust build that is designed with different pipe sizes? 4 State Trucks offers the high quality reducer that...
    09-080100165
    SKU:
    09-080100165
    Diameter Options:
    6 Inch
    Truck Class:
    Universal
    Length Options:
    8 Inch
    Material Options:
    Aluminized Steel
    Make:
    Universal Items
    Product Type:
    Exhaust
    $45.59
    Qty in Cart: 0
    Price:
    $45.59
    Subtotal:
  • BESTfit Aluminized Exhaust Adapter Reducer 6 ID X 4 OD X 8 Inch

    BESTfit Aluminized Exhaust Adapter Reducer 6 ID X 4 OD X 8 Inch

    BESTFIT TRUCK PARTS

    $88.99
    BESTfit 6 To 4 Inch I.D.-O.D. X 8 Inch OAL Aluminized Steel Reducer PipeAre you building a custom exhaust that requires different pipe sizes? 4 State Trucks offers this high quality reducer that is...
    09-080100164
    SKU:
    09-080100164
    Diameter Options:
    6 Inch
    Truck Class:
    Universal
    Length Options:
    8 Inch
    Material Options:
    Aluminized Steel
    Make:
    Universal Items
    Product Type:
    Exhaust
    $88.99
    Qty in Cart: 0
    Price:
    $88.99
    Subtotal:
  • BESTfit Aluminized Exhaust Adapter Reducer 6 ID X 4 ID X 8 Inch

    BESTfit Aluminized Exhaust Adapter Reducer 6 ID X 4 ID X 8 Inch

    BESTFIT TRUCK PARTS

    $70.99
    BESTfit 6 To 4 Inch I.D.-I.D. X 8 Inch OAL Aluminized Steel Reducer PipeAre you building a custom exhaust that requires different pipe sizes? 4 State Trucks offers this high quality reducer to...
    09-080100163
    SKU:
    09-080100163
    Truck Class:
    Universal
    Diameter Options:
    6 Inch
    Length Options:
    8 Inch
    Material Options:
    Aluminized Steel
    Make:
    Universal Items
    Product Type:
    Exhaust
    Ready To Ship:
    Yes
    $70.99
    Qty in Cart: 0
    Price:
    $70.99
    Subtotal:
  • BESTfit Aluminized Exhaust Adapter Reducer 5 OD X 4 OD X 8 Inch

    BESTfit Aluminized Exhaust Adapter Reducer 5 OD X 4 OD X 8 Inch

    BESTFIT TRUCK PARTS

    $45.60
    BESTfit 5 To 4 Inch O.D.-O.D. X 8 Inch OAL Aluminized Steel Reducer PipeAre you building a custom exhaust that requires different pipe sizes? 4 State Trucks offers this high quality reducer to...
    09-080100162
    SKU:
    09-080100162
    Truck Class:
    Universal
    Diameter Options:
    5 Inch
    Length Options:
    8 Inch
    Material Options:
    Aluminized Steel
    Make:
    Universal Items
    Product Type:
    Exhaust
    $45.60
    Qty in Cart: 0
    Price:
    $45.60
    Subtotal:
  • BESTfit Aluminized Exhaust Reducer 5 OD X 4 ID X 8 Inch

    BESTfit Aluminized Exhaust Reducer 5 OD X 4 ID X 8 Inch

    BESTFIT TRUCK PARTS

    $29.99
    5 To 4 Inch OD-ID X 8 Inch OAL Aluminized Steel Reducer PipeAre you building a custom exhaust that requires different pipe sizes? 4 State Trucks offers this high quality reducer that is made to last...
    09-080100161
    SKU:
    09-080100161
    Diameter Options:
    5 Inch
    Truck Class:
    Universal
    Length Options:
    8 Inch
    Material Options:
    Aluminized Steel
    Make:
    Universal Items
    Product Type:
    Exhaust
    Ready To Ship:
    Yes
    $29.99
    Qty in Cart: 0
    Price:
    $29.99
    Subtotal:
  • BESTfit Aluminized Exhaust Adapter Reducer 5 ID X 4 OD X 8 Inch

    BESTfit Aluminized Exhaust Adapter Reducer 5 ID X 4 OD X 8 Inch

    BESTFIT TRUCK PARTS

    $42.43
    BESTfit 5 To 4 Inch I.D.-O.D. X 8 Inch OAL Aluminized Steel Reducer PipeDo you want to ensure your pipe connections fit perfectly and look great? 4 State Trucks high quality reducer that will...
    09-080100160
    SKU:
    09-080100160
    Diameter Options:
    5 Inch
    Truck Class:
    Universal
    Length Options:
    8 Inch
    Material Options:
    Aluminized Steel
    Make:
    Universal Items
    Product Type:
    Exhaust
    Ready To Ship:
    Yes
    $42.43
    Qty in Cart: 0
    Price:
    $42.43
    Subtotal:
  • FREE SHIPPING OVER $249
    BESTfit Aluminized Exhaust Reducer 5 ID X 4 ID X 8 Inch

    BESTfit Aluminized Exhaust Reducer 5 ID X 4 ID X 8 Inch

    BESTFIT TRUCK PARTS

    $34.84
    BESTfit 5 To 4 Inch ID-ID X 8 Inch OAL Aluminized Steel Reducer PipeAre you looking for a reducer to ensure your exhaust pipes fit perfectly? 4 State Trucks offers this high quality reducer that will...
    09-080100159
    SKU:
    09-080100159
    Truck Class:
    Universal
    Diameter Options:
    5 Inch
    Length Options:
    8 Inch
    Material Options:
    Aluminized Steel
    Make:
    Universal Items
    Product Type:
    Exhaust
    Ready To Ship:
    Yes
    $34.84
    Qty in Cart: 0
    Price:
    $34.84
    Subtotal:
  • BESTfit Aluminized Exhaust Adapter Reducer 4 OD X 3 OD X 8 Inch

    BESTfit Aluminized Exhaust Adapter Reducer 4 OD X 3 OD X 8 Inch

    BESTFIT TRUCK PARTS

    $21.74
    BESTfit 4 To 3 Inch O.D.-O.D. X 8 Inch OAL Aluminized Steel Reducer Pipe4 State Trucks offers this high quality reducer that will securely connect two different sized pipes on an exhaust with ease...
    09-080100158
    SKU:
    09-080100158
    Truck Class:
    Universal
    Material Options:
    Aluminized Steel
    Make:
    Universal Items
    Diameter Options:
    4 Inch
    Length Options:
    8 Inch
    Product Type:
    Exhaust
    $21.74
    Qty in Cart: 0
    Price:
    $21.74
    Subtotal:
  • BESTfit Aluminized Exhaust Reducer 4 OD X 3 ID X 6 Inch

    BESTfit Aluminized Exhaust Reducer 4 OD X 3 ID X 6 Inch

    BESTFIT TRUCK PARTS

    $22.04
    BESTfit 4 To 3 Inch OD-ID X 6 Inch OAL Aluminized Steel Reducer PipeSupport proper exhaust routing with this BESTfit aluminized steel exhaust reducer built for dependable performance in demanding...
    09-080100157
    SKU:
    09-080100157
    Diameter Options:
    4 Inch
    Truck Class:
    Universal
    Length Options:
    8 Inch
    Material Options:
    Aluminized Steel
    Make:
    Universal Items
    Product Type:
    Exhaust
    $22.04
    Qty in Cart: 0
    Price:
    $22.04
    Subtotal:
  • BESTfit Aluminized Exhaust Adapter Reducer 4 OD X 3-1/2 OD X 8 Inch

    BESTfit Aluminized Exhaust Adapter Reducer 4 OD X 3-1/2 OD X 8 Inch

    BESTFIT TRUCK PARTS

    $26.71
    BESTfit 4 To 3.5 Inch O.D.-O.D. X 8 Inch OAL Aluminized Steel Reducer PipeTransform your exhaust's appearance with the BESTfit 4 to 3.5 Inch OD-OD Aluminized Steel Reducer Pipe. Offering a precise...
    09-080100156
    SKU:
    09-080100156
    Diameter Options:
    4 Inch
    Length Options:
    8 Inch
    Material Options:
    Aluminized Steel
    Make:
    Universal Items
    Truck Class:
    Heavy Duty
    Product Type:
    Exhaust
    $26.71
    Qty in Cart: 0
    Price:
    $26.71
    Subtotal:
  • BESTfit Aluminized Exhaust Reducer 4 OD X 3-1/2 ID X 8 Inch

    BESTfit Aluminized Exhaust Reducer 4 OD X 3-1/2 ID X 8 Inch

    BESTFIT TRUCK PARTS

    $24.93
    BESTfit 4 To 3.5 Inch OD-ID X 8 Inch OAL Aluminized Steel Reducer PipeUpgrade your exhaust system with our Aluminized Exhaust Reducer, designed to transition from a 4-inch OD to a 3.5-inch ID over an...
    09-080100155
    SKU:
    09-080100155
    Diameter Options:
    4 Inch
    Length Options:
    8 Inch
    Material Options:
    Aluminized Steel
    Make:
    Universal Items
    Truck Class:
    Heavy Duty
    Product Type:
    Exhaust
    $24.93
    Qty in Cart: 0
    Price:
    $24.93
    Subtotal:
  • BESTfit Aluminized Exhaust Adapter Reducer 4 ID X 3 OD X 8 Inch

    BESTfit Aluminized Exhaust Adapter Reducer 4 ID X 3 OD X 8 Inch

    BESTFIT TRUCK PARTS

    $30.75
    BESTfit 4 To 3 Inch O.D.-O.D. X 8 Inch OAL Aluminized Steel Reducer PipeAre you building a custom exhaust that requires different pipe sizes? 4 State Trucks offers this high quality reducer to...
    09-080100154
    SKU:
    09-080100154
    Diameter Options:
    4 Inch
    Truck Class:
    Universal
    Length Options:
    8 Inch
    Material Options:
    Aluminized Steel
    Make:
    Universal Items
    Product Type:
    Exhaust
    $30.75
    Qty in Cart: 0
    Price:
    $30.75
    Subtotal:
  • BESTfit Aluminized Exhaust Adapter Reducer 4 ID X 3-1/2 OD X 8 Inch

    BESTfit Aluminized Exhaust Adapter Reducer 4 ID X 3-1/2 OD X 8 Inch

    BESTFIT TRUCK PARTS

    $30.75
    BESTfit 4 To 3.5 Inch ID-OD X 8 Inch OAL Aluminized Steel Reducer PipeIntroducing the BESTfit Aluminized Exhaust Reducer, expertly designed to connect a 4-inch ID to a 3.5-inch OD over an 8-inch...
    09-080100153
    SKU:
    09-080100153
    Diameter Options:
    4 Inch
    Length Options:
    8 Inch
    Material Options:
    Aluminized Steel
    Make:
    Universal Items
    Truck Class:
    Heavy Duty
    Product Type:
    Exhaust
    $30.75
    Qty in Cart: 0
    Price:
    $30.75
    Subtotal:
  • BESTfit Aluminized Exhaust Adapter Reducer 4 ID X 3-1/2 ID X 8 Inch

    BESTfit Aluminized Exhaust Adapter Reducer 4 ID X 3-1/2 ID X 8 Inch

    BESTFIT TRUCK PARTS

    $32.89
    BESTfit 4 To 3.5 Inch ID-ID X 8 Inch OAL Aluminized Steel Reducer PipeAchieve a great fit for your exhaust with the BESTfit 4 to 3.5 Inch ID-ID Aluminized Steel Reducer Pipe. This 8-inch-long reducer...
    09-080100152
    SKU:
    09-080100152
    Diameter Options:
    4 Inch
    Length Options:
    8 Inch
    Material Options:
    Aluminized Steel
    Make:
    Universal Items
    Truck Class:
    Heavy Duty
    Product Type:
    Exhaust
    $32.89
    Qty in Cart: 0
    Price:
    $32.89
    Subtotal:
  • BESTfit 8 OD X 20 Inch OAL 90 Degree Tangent Cut Cold Rolled Steel Elbow

    BESTfit 8 OD X 20 Inch OAL 90 Degree Tangent Cut Cold Rolled Steel Elbow

    BESTFIT TRUCK PARTS

    $338.99
    BESTfit 8 Inch Diameter X 20 Inch OAL 90 Degree Tangent Cut Cold Rolled Steel Elbow* High Quality Elbow* Tangent Cut* Made Of Cold Rolled Steel* Dimensions  - 40 Inch Overall Length (20x20)  - 8 Inch...
    09-080100145
    SKU:
    09-080100145
    Truck Class:
    Universal
    Diameter Options:
    8 Inch
    Style Options:
    Elbow
    Material Options:
    Aluminized Steel
    Degree Options:
    90
    Make:
    Universal Items
    Length Options:
    20 Inch
    Product Type:
    Exhaust
    $338.99
    Qty in Cart: 0
    Price:
    $338.99
    Subtotal:
  • BESTfit 6 ID/OD X 24 Inch OAL 90 Degree Chrome-Plated Steel Elbow

    BESTfit 6 ID/OD X 24 Inch OAL 90 Degree Chrome-Plated Steel Elbow

    BESTFIT TRUCK PARTS

    $375.99
    BESTfit 6 Inch ID-O.D. X 24 Inch OAL 90 Degree Chrome-Plated Steel Elbow* High Quality Elbow* Chrome-Plated Steel * Dimensions  - 48 Inch Overall Length (24x24)  - 6 Inch ID/OD  - 90 Degree Angle  -...
    09-080100144
    SKU:
    09-080100144
    Diameter Options:
    6 Inch
    Truck Class:
    Universal
    Style Options:
    Elbow
    Material Options:
    Steel
    Degree Options:
    90
    Make:
    Universal Items
    Finish Options:
    Chrome-Plated
    Length Options:
    24 Inch
    Product Type:
    Exhaust
    $375.99
    Qty in Cart: 0
    Price:
    $375.99
    Subtotal:
  • Total: items /

Adding your products to cart

Your Kenworth W900A is a true classic. Give it the exhaust system it deserves with high-quality aftermarket parts built to boost performance, cut emissions, and add custom style to your rig.

Upgrade Your Kenworth W900A’s Exhaust System the Right Way

Whether you're restoring a vintage icon or keeping your daily driver rolling smooth, upgrading your exhaust setup has serious benefits: - Better airflow for more efficient engine performance - Improved fuel economy and reduced backpressure - Lower emissions with reliable mufflers and stack setups - Iconic style with polished chrome stacks and classic elbow piping - Long-term durability with stainless steel clamps and brackets Here's what you can start upgrading!  - Chrome Stacks & Tops: Give your W900A a bold, custom look - Mufflers & Elbows: Cut noise, improve flow, and maintain that signature Kenworth growl - Exhaust Kits: Complete setups to save time and keep your system running right - Mounting Brackets & Clamps: Secure your setup with heavy-duty hardware that holds
Every part in this lineup is built to fit your W900A like a glove. While you’re enhancing your exhaust, consider power modifications like Kenworth W900A turbochargers and manifolds or swapping out your T300/T AC and heating components for your classic rig. Give it the exhaust system it deserves with high-quality aftermarket parts built to boost performance, cut emissions, and add custom style to your rig.

Frequently Asked Questions About Kenworth W900A Exhaust Parts

What years and models are compatible with these W900A exhaust parts?

Our Kenworth W900A exhaust parts are designed specifically for W900A models produced from 1961 to 1986. While many components share similar mounting patterns across these years, we strongly recommend verifying your truck's specific year and engine configuration before ordering. Key differences exist between pre-1973 and post-1973 models due to emissions regulations. If you're unsure about compatibility, please contact us with your OEM or model year, and we'll help ensure proper fitment.

Are these exhaust stacks chrome or stainless steel, and what's the difference in durability?

We offer both chrome-plated and polished stainless steel options. Chrome stacks provide that classic mirror finish but require regular polishing and may show pitting after 3-5 years depending on your climate and road conditions. Stainless steel stacks cost approximately 20-30% more initially but resist corrosion better and maintain their appearance with less maintenance. For trucks operating in salt belt states or coastal areas, stainless steel typically proves more cost-effective long-term.

What tools and time are required for a typical exhaust stack installation?

A standard exhaust stack installation requires basic hand tools including socket wrenches, clamps, and potentially a sawzall for removing old components. Most experienced mechanics complete the job in 2-4 hours. Common challenges include rusted mounting brackets and ensuring proper alignment to prevent cab contact. We recommend having exhaust sealant, new clamps, and mounting hardware on hand. Professional installation typically runs $200-400 depending on your location and the complexity of your setup.

What's the difference between straight pipes, curved stacks, and miter cut options?

Straight pipes offer maximum exhaust flow and the classic long-hood look, typically extending 36-48 inches above the cab. Curved stacks angle away from the cab to reduce soot buildup on the sleeper and are popular for over-the-road applications. Miter cuts affect both appearance and sound - standard cuts provide moderate tone, while aggressive angles create louder exhaust notes.

How do I prevent exhaust leaks at the connections and what maintenance is required?

Exhaust leaks commonly occur at clamp connections and flex pipe joints. Use high-temperature exhaust sealant rated for at least 1200?F at all connections during installation. Retorque clamps after the first 500 miles as thermal cycling can cause loosening. Check connections monthly and look for black soot trails indicating leaks. Chrome stacks need polishing every 2-4 weeks to prevent discoloration, while stainless requires only periodic cleaning with appropriate metal polish. Replace exhaust rain caps annually as the springs weaken over time.


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