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Kenworth T300-T450 Deck Plates & Air Line Boxes

Upgrade your Kenworth T300 or T450 with deck plates and air line boxes. Pick cutouts for electric plugs or trailer air. Choose flush-mount or surface-mount styles in chrome or aluminum. These durable parts look great and perform even better. Find your perfect fit at 4 State Trucks.
  • Product
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  • FREE SHIPPING
    CSM Stainless Steel Trough Style Flush-Mount Air Line Box

    CSM Stainless Steel Trough Style Flush-Mount Air Line Box

    CHROME SHOP MAFIA

    $303.99 - $337.99
    The Stainless Steel Trough Style Flush Mount Air Line Box is a must-have to organize air lines and electrical connections efficiently. Constructed from durable 304 stainless steel, this air line box...
    PPR_202175
    SKU:
    PPR_202175
    Truck Class:
    Universal
    Location:
    Made In USA
    Material Options:
    Stainless Steel
    Make:
    Universal Items
    Style Options:
    Flush Mount
    Truck Class:
    Heavy Duty
    Product Type:
    Frame & Chassis
    Ready To Ship:
    Yes
    $303.99 - $337.99
    Qty in Cart: 0
    Price:
    $303.99 - $337.99
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  • On Sale
    Stainless Steel In-Frame Deck Plate For Trucks W/ 27 Inches Between Frame Rails

    Stainless Steel In-Frame Deck Plate For Trucks W/ 27 Inches Between Frame Rails

    IOWA CUSTOMS

    $398.69 - $855.89
    Optimize your setup with the Stainless Steel Flush Mount In-Frame Deck Plate, a stellar upgrade for truck owners looking for both functionality and style. Made from #8 304 polished stainless steel,...
    PPR_202165
    SKU:
    PPR_202165
    Truck Class:
    Universal
    Material Options:
    Stainless Steel
    Make:
    Universal Items
    Truck Class:
    Heavy Duty
    Product Type:
    Frame & Chassis
    Ready To Ship:
    Yes
    Length Options:
    36 Inch
    Length Options:
    84 Inch
    Type Options:
    Flush Mount
    Length Options:
    60 Inch
    Finish Options:
    Polished
    Location:
    Made In USA
    Length Options:
    72 Inch
    Style Options:
    In Frame
    Width Options:
    27 Inch
    Length Options:
    48 Inch
    Length Options:
    96 Inch
    $398.69 - $855.89
    Qty in Cart: 0
    Price:
    $398.69 - $855.89
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  • Smooth Aluminum In-Frame Deck Plate Flush Mount

    Smooth Aluminum In-Frame Deck Plate Flush Mount

    IOWA CUSTOMS

    $363.99 - $794.99
    Improve your ride with the Smooth Aluminum Flush Mount In-Frame Deck Plate which offers exceptional durability and a polished look. Crafted from high-quality aluminum, this deck plate is designed to...
    PPR_202164
    SKU:
    PPR_202164
    Truck Class:
    Universal
    Material Options:
    Aluminum
    Make:
    Universal Items
    Finish Options:
    Smooth
    Style Options:
    Flush Mount
    Truck Class:
    Heavy Duty
    Product Type:
    Frame & Chassis
    Ready To Ship:
    Yes
    $363.99 - $794.99
    Qty in Cart: 0
    Price:
    $363.99 - $794.99
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  • Diamond Plate Aluminum In-Frame Deck Plate Flush-Mount

    Diamond Plate Aluminum In-Frame Deck Plate Flush-Mount

    IOWA CUSTOMS

    $498.99 - $1,129.99
    Upgrade your look with the Diamond Plate Aluminum Flush Mount In-Frame Deck Plate, a robust accessory designed for adding more shine. Made from high-strength diamond tread aluminum, this deck plate...
    PPR_202163
    SKU:
    PPR_202163
    Truck Class:
    Universal
    Material Options:
    Aluminum
    Make:
    Universal Items
    Finish Options:
    Diamond Plate
    Truck Class:
    Heavy Duty
    Product Type:
    Frame & Chassis
    $498.99 - $1,129.99
    Qty in Cart: 0
    Price:
    $498.99 - $1,129.99
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  • FREE SHIPPING OVER $249
    CSM 34 Inch Stainless Steel Deck Plates With Length Options

    CSM 34 Inch Stainless Steel Deck Plates With Length Options

    CHROME SHOP MAFIA

    $225.99 - $1,044.99
    The CSM 34 Inch Wide Stainless Steel Deck Plate is made from high-quality 304 stainless steel, and available in various lengths ranging from 2 feet to 10 feet. Each deck plate comes complete with...
    PPR_202162
    SKU:
    PPR_202162
    Location:
    Made In USA
    Truck Class:
    Heavy Duty
    Material Options:
    Stainless Steel
    Make:
    Universal Items
    Product Type:
    Frame & Chassis
    Ready To Ship:
    Yes
    $225.99 - $1,044.99
    Qty in Cart: 0
    Price:
    $225.99 - $1,044.99
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  • CSM 34 Inch Wide Diamond Plate Aluminum Deck Plates

    CSM 34 Inch Wide Diamond Plate Aluminum Deck Plates

    CHROME SHOP MAFIA

    $181.99 - $819.99
    Add dependable footing and bold styling to your truck with the CSM 34 Inch Wide Diamond Plate Aluminum Deck Plate. Built from durable aluminum with a raised diamond tread pattern, it provides...
    PPR_202161
    SKU:
    PPR_202161
    Truck Class:
    Heavy Duty
    Location:
    Made In USA
    Material Options:
    Aluminum
    Make:
    Universal Items
    Finish Options:
    Diamond Plate
    Style Options:
    Surface Mount
    Product Type:
    Frame & Chassis
    Ready To Ship:
    Yes
    Width Options:
    34 Inch
    Length Options:
    48 Inch
    $181.99 - $819.99
    Qty in Cart: 0
    Price:
    $181.99 - $819.99
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  • Merritt Aluminum Dyna Deck Top Mount Deck Plate 33.25 Inch Wide W/ Height Options

    Merritt Aluminum Dyna Deck Top Mount Deck Plate 33.25 Inch Wide W/ Height Options

    MERRITT

    $221.99 - $644.99
    For truck owners seeking strength, style, and utility, the Merritt 33.25 Inch Wide Aluminum Dyna Deck Top Mount Deck Plate delivers unmatched performance. Made from premium aluminum, it provides a...
    PPR_201929
    SKU:
    PPR_201929
    Truck Class:
    Universal
    Location:
    Made In USA
    Material Options:
    Aluminum
    Make:
    Universal Items
    Truck Class:
    Heavy Duty
    Product Type:
    Frame & Chassis
    Ready To Ship:
    Yes
    Length Options:
    28 Inch
    Width Options:
    33 Inch
    Length Options:
    47 Inch
    Length Options:
    18 1/2 Inch
    Length Options:
    65 Inch
    Length Options:
    37 1/2 Inch
    Position:
    Kit Full
    Type Options:
    Top Mount
    Style Options:
    Ribbed
    $221.99 - $644.99
    Qty in Cart: 0
    Price:
    $221.99 - $644.99
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  • Merritt 30.25 Inch Aluminum Flush Mount Dyna Deck Plate

    Merritt 30.25 Inch Aluminum Flush Mount Dyna Deck Plate

    MERRITT

    $227.99 - $753.99
    Upgrade your truck bed or trailer with the Merritt 30.25 Inch Aluminum Flush Mount Dyna Deck Plate. Available in multiple sizes-18.5 x 30.25, 28 x 30.25, 37.5 x 30.25, 56 x 30.25, and 65.25 x 30.25...
    PPR_201926
    SKU:
    PPR_201926
    Location:
    Made In USA
    Truck Class:
    Universal
    Material Options:
    Aluminum
    Make:
    Universal Items
    Style Options:
    Flush Mount
    Truck Class:
    Heavy Duty
    Product Type:
    Frame & Chassis
    Length Options:
    46 Inch
    Ready To Ship:
    Yes
    Length Options:
    56 Inch
    Length Options:
    18 1/2 Inch
    Length Options:
    28 Inch
    Length Options:
    65 Inch
    Width Options:
    30 Inch
    Length Options:
    37 1/2 Inch
    Type Options:
    Flush Mount
    Length Options:
    74 Inch
    $227.99 - $753.99
    Qty in Cart: 0
    Price:
    $227.99 - $753.99
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  • On Sale
    FREE SHIPPING OVER $249
    Limited Quantity Available
    S2 Style Billet Aluminum Step Plate W/ Flat Ends For Side Boxes And Deck Plates

    S2 Style Billet Aluminum Step Plate W/ Flat Ends For Side Boxes And Deck Plates

    IOWA CUSTOMS

    $75.23 - $503.99
    The Billet Aluminum Step Plate in the S2 style with flat ends is a high-quality option specifically designed for side boxes and deck plates. Measuring 6 inches in width and 12 or 20 inches in length,...
    PPR_201332
    SKU:
    PPR_201332
    Truck Class:
    Universal
    Material Options:
    Aluminum
    Make:
    Universal Items
    Truck Class:
    Heavy Duty
    Product Type:
    Frame & Chassis
    Ready To Ship:
    Yes
    $75.23 - $503.99
    Qty in Cart: 0
    Price:
    $75.23 - $503.99
    Subtotal:
  • FREE SHIPPING OVER $249
    S1 Style Billet Aluminum Step Plate With Concave Ends For Side Boxes & Deck Plates

    S1 Style Billet Aluminum Step Plate With Concave Ends For Side Boxes & Deck Plates

    IOWA CUSTOMS

    $152.99 - $483.99
    Maximize your truck with the S1 Style Billet Aluminum Step Plate with Concave Ends, an ideal accessory crafted for both functionality and aesthetics. This step plate measures 6 inches in width and 20...
    PPR_201146
    SKU:
    PPR_201146
    Truck Class:
    Universal
    Material Options:
    Aluminum
    Make:
    Universal Items
    Truck Class:
    Heavy Duty
    Ready To Ship:
    Yes
    Product Type:
    Frame & Chassis
    $152.99 - $483.99
    Qty in Cart: 0
    Price:
    $152.99 - $483.99
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  • 10 Foot Deck Plate, Flush Mount. Modular Style With 13 Planks.

    10 Foot Deck Plate, Flush Mount. Modular Style With 13 Planks.

    MERRITT

    $1,181.99
    10 Foot Deck Plate, Flush Mount. Modular Style With 13 Planks* High Quality Deck Plate* 10 Foot* Flush Mount * Modular Style* With 13 Planks* Made In USA* Sold Individually* Warranty On Deck Plates...
    4413
    SKU:
    4413
    Length Options:
    120 Inch
    Truck Class:
    Heavy Duty
    Location:
    Made In USA
    Style Options:
    Flush Mount
    Material Options:
    Aluminum
    Make:
    Universal Items
    Product Type:
    Frame & Chassis
    $1,181.99
    Qty in Cart: 0
    Price:
    $1,181.99
    Subtotal:
  • Merritt 30.25 X 92.5 Inch Dyna Deck Plate- Flush Mount

    Merritt 30.25 X 92.5 Inch Dyna Deck Plate- Flush Mount

    MERRITT

    $964.99
    30.25 X 92.5 Inch Flush Mount Deck Plate By MerrittThe Merritt 30.25 92.5 Inch Dyna Deck Plate - Flush Mount is engineered to deliver maximum functionality and durability for any truck bed. Its flush...
    4410
    SKU:
    4410
    Location:
    Made In USA
    Truck Class:
    Heavy Duty
    Style Options:
    Flush Mount
    Material Options:
    Aluminum
    Make:
    Universal Items
    Length Options:
    92 Inch
    Product Type:
    Frame & Chassis
    Ready To Ship:
    Yes
    $964.99
    Qty in Cart: 0
    Price:
    $964.99
    Subtotal:
  • Dyna-Deck Top Mount Modular Deck Cover, 56 L X 33.25 W IN

    Dyna-Deck Top Mount Modular Deck Cover, 56 L X 33.25 W IN

    MERRITT

    $541.99
    56 L X 33.25 W Inch Deck Plate W/ Slide Together Planks* High Quality Deck Plate* Dimensions:   - 56 Length   - 33.25 Width* With Top Mount With Easy Slide Together Planks* Has Non Skid Ribbed Deck...
    436
    SKU:
    436
    Location:
    Made In USA
    Truck Class:
    Heavy Duty
    Length Options:
    56 Inch
    Material Options:
    Aluminum
    Make:
    Universal Items
    Product Type:
    Frame & Chassis
    $541.99
    Qty in Cart: 0
    Price:
    $541.99
    Subtotal:
  • Recessed Air Line Box Stainless Steel W/ Holes For Electric & 2 Air Hook Ups

    Recessed Air Line Box Stainless Steel W/ Holes For Electric & 2 Air Hook Ups

    IOWA CUSTOMS

    $608.99
    Air Line Box* High Quality Recessed Air Line Box* Made Of Stainless Steel * With Openings for 1 Electric And 2 Air Hook Up* Sold Individually* Warranty On Recessed Air Line Box Against Defects In...
    09-0504318
    SKU:
    09-0504318
    Truck Class:
    Universal
    Make:
    Universal Items
    Material Options:
    Stainless Steel
    Style Options:
    Flush Mount
    Product Type:
    Frame & Chassis
    $608.99
    Qty in Cart: 0
    Price:
    $608.99
    Subtotal:
  • FREE SHIPPING
    Trough Style Air Line Box Stainless Steel By Brunner

    Trough Style Air Line Box Stainless Steel By Brunner

    BRUNNER FABRICATION

    $618.99
    20.25 X 15 Inch Trough Style Air Line Box By Brunner FabricationProtect the air line connection on your truck with this high quality trough style airline box by Brunners Fabrication Inc. It is made...
    09-0504310
    SKU:
    09-0504310
    Length Options:
    20 Inch
    Truck Class:
    Universal
    Material Options:
    Stainless Steel
    Make:
    Universal Items
    Style Options:
    Surface Mount
    Product Type:
    Air, Electrical, & Safety
    $618.99
    Qty in Cart: 0
    Price:
    $618.99
    Subtotal:
  • Stainless Steel Airline Box W/ 2 Electric Plug Holes & Bolted In Ends

    Stainless Steel Airline Box W/ 2 Electric Plug Holes & Bolted In Ends

    PHOENIX DESIGN

    $291.99
    SS Air Line Box W/ 2 Electric Plug Holes & Bolted In EndsThis air-line box uses strong 304 stainless steel to keep your electrical connections safe. It includes two handy electrical plug holes with...
    09-0504308
    SKU:
    09-0504308
    Truck Class:
    Universal
    Material Options:
    Stainless Steel
    Make:
    Universal Items
    Product Type:
    Frame & Chassis
    $291.99
    Qty in Cart: 0
    Price:
    $291.99
    Subtotal:
  • Air Line Box Stainless Steel 32 Inch W/ Hole For Single Electric Plug- Bolted In Ends

    Air Line Box Stainless Steel 32 Inch W/ Hole For Single Electric Plug- Bolted In Ends

    PHOENIX DESIGN

    $277.99
    Airline Box W/ Single Electric PlugCrafted from stainless steel, the Air Line Box incorporates two cutouts for air lines. For increased durability and security, its ends are bolted. The overall...
    09-0504307
    SKU:
    09-0504307
    Truck Class:
    Universal
    Length Options:
    32 Inch
    Style Options:
    Surface Mount
    Material Options:
    Stainless Steel
    Make:
    Universal Items
    Product Type:
    Frame & Chassis
    Ready To Ship:
    Yes
    $277.99
    Qty in Cart: 0
    Price:
    $277.99
    Subtotal:
  • FREE SHIPPING
    Air Line Box Diamond Plate Aluminum W/ Single Electrical Plug Hole by CSM

    Air Line Box Diamond Plate Aluminum W/ Single Electrical Plug Hole by CSM

    CHROME SHOP MAFIA

    $454.99
    Aluminum Air Line Box w/ Single Electrical Plug Hole By Chrome Shop MafiaHide unsightly connectors on the back of your truck with this CSM Air Line Box. Made of lightweight aluminum with diamond...
    09-0504200
    SKU:
    09-0504200
    Truck Class:
    Universal
    Location:
    Made In USA
    Material Options:
    Aluminum
    Make:
    Universal Items
    Finish Options:
    Diamond Plate
    Style Options:
    Surface Mount
    Product Type:
    Frame & Chassis
    $454.99
    Qty in Cart: 0
    Price:
    $454.99
    Subtotal:
  • Smooth Aluminum Recessed Air Line Box With Holes For 7-Way Plug, Air Lines

    Smooth Aluminum Recessed Air Line Box With Holes For 7-Way Plug, Air Lines

    IOWA CUSTOMS

    $590.99
    Smooth Aluminum Recessed Air Line BoxThis quality Series 7 Iowa Customs recessed air line box fits most trucks. It is made of lightweight smooth aluminum and has pre-cut openings for trailer air...
    09-0504103
    SKU:
    09-0504103
    Truck Class:
    Universal
    Finish Options:
    Smooth
    Make:
    Universal Items
    Style Options:
    Flush Mount
    Material Options:
    Aluminum
    Product Type:
    Frame & Chassis
    $590.99
    Qty in Cart: 0
    Price:
    $590.99
    Subtotal:
  • Smooth Aluminum Air Line Box W/ 45 Degree Front, Flange, Trailer Air, 7-Way Hook-Up

    Smooth Aluminum Air Line Box W/ 45 Degree Front, Flange, Trailer Air, 7-Way Hook-Up

    IOWA CUSTOMS

    $503.99
    Smooth Aluminum Custom Air Line Box W/ Trailer, Air & 1 7-Way Hookup* High Quality Airline Box* Smooth Aluminum * 45 Degree Front * With Flange * Trailer Air And One 7 Way Hook Up* Sold Individually*...
    09-0504102
    SKU:
    09-0504102
    Truck Class:
    Universal
    Make:
    Universal Items
    Material Options:
    Aluminum
    Style Options:
    Surface Mount
    Finish Options:
    Smooth
    Product Type:
    Frame & Chassis
    $503.99
    Qty in Cart: 0
    Price:
    $503.99
    Subtotal:
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Adding your products to cart

Enhance your Kenworth T300 or T450 with aftermarket deck plates and air line boxes built for durability, safety, and style. These upgrades make it easier to manage trailer hookups, protect your frame, and give your truck a cleaner, more professional appearance.

Upgrade with New Kenworth T300/T450 Catwalk & Deckplate Designs

Choose from aluminum, stainless steel, or diamond tread deck plates designed to handle the demands of daily use. Aluminum offers a lightweight, paintable surface, while stainless steel provides a bright, polished shine that resists corrosion. The diamond plate finish adds extra grip-ideal for climbing, loading, and working around your rig. The air line boxes in this lineup keep your air, electrical, and lighting hookups secure and organized. Go for a recessed or flush-mount box if you want a smooth, integrated setup, or choose a top-mounted box for quick, easy access. Air line boxes can be ordered with blank or pre-drilled designs to fit single or dual trailer hookups. Combine your upgrade with Kenworth T300/T450 toolboxes, Kenworth T300/T450 filler panels and Kenworth T450 or T300 frame steps. Whether you're upgrading your rig or replacing worn parts, these Kenworth T300 and T450 deck plates and air line boxes offer the reliability, protection, and polished look that every driver and fleet owner can appreciate. Built tough for real road conditions, they deliver lasting performance and everyday convenience.

Frequently Asked Questions About Kenworth T300-T450 Deck Plates & Air Line Boxes

What are deck plates and air line boxes used for on my Kenworth?

Deck plates are the flat metal panels mounted behind the cab, typically covering the frame rails and providing a walkway or work surface, while air line boxes are the enclosures that house and protect the air and electrical lines that run between the tractor and trailer. Together, these components protect vital lines from road debris, weather, and wear while giving the back-of-cab area a finished, functional look.

Will these parts fit my specific Kenworth T300, T400, T440, or T450 model?

Fitment can vary by model year and cab configuration, so it's important to check the listed specifications for each part before ordering. If you're unsure whether a deck plate or air line box will match your truck's frame width or mounting points, reach out to our team with your VIN or model details and we'll help confirm compatibility.

What materials are these deck plates and air line boxes made from, and what finish options are available?

Most deck plates and air line boxes in this category are constructed from steel or aluminum, with finish options ranging from raw or painted steel to polished or brushed aluminum. Aluminum options tend to resist corrosion better and offer a lighter-weight, brighter appearance, while steel options are often chosen for added durability under heavy use.

How difficult is it to install a replacement deck plate or air line box?

Installation difficulty depends on the specific part, but many deck plates and air line boxes are designed to bolt into the existing mounting holes used by the factory components, making replacement relatively straightforward with basic hand tools. Some fabricated or aftermarket designs may require minor drilling or bracket adjustments, so it's a good idea to review any included instructions or fitment notes before starting the job.

Can I upgrade to a different style of air line box or deck plate for better protection or looks?

Yes, many customers replace factory deck plates and air line boxes with heavier-gauge or styled aftermarket versions to improve durability, add a custom look, or repair damage from rust and road wear. When upgrading, just make sure the new part is compatible with your frame width and existing air and electrical line routing to avoid modification headaches during install.


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