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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.
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    Aluminum Deck Plate 18 Inch Sectional with Air line Box With Openings For Trailer Air & 7-Way Hookups

    Aluminum Deck Plate 18 Inch Sectional with Air line Box With Openings For Trailer Air & 7-Way Hookups

    IOWA CUSTOMS

    $456.99
    Sectional Deck Plate 18 Inch Aluminum with Air line BoxThis smooth aluminum deck plate measures 18 inches with a recessed air line box for easy integration of air lines. The box is designed to...
    09-0503013
    SKU:
    09-0503013
    Truck Class:
    Universal
    Make:
    Universal Items
    Style Options:
    Flush Mount
    Material Options:
    Aluminum
    Product Type:
    Frame & Chassis
    Ready To Ship:
    Yes
    $456.99
    Qty in Cart: 0
    Price:
    $456.99
    Subtotal:
  • On Sale
    Limited Quantity Available
    12 Inch Aluminum Sectional Deck Plate Filler Panel

    12 Inch Aluminum Sectional Deck Plate Filler Panel

    IOWA CUSTOMS

    Now: $118.99
    Was: $169.99
    Sectional Deck Plate 12 Inch Aluminum Filler Panel* Made Of High Quality Aluminum* 12 Inch* Made In USA* Sold Individually* Warranty On Deck Plate Filler Panels Against Defects In Workmanship &...
    09-0503012
    SKU:
    09-0503012
    Truck Class:
    Universal
    Make:
    Universal Items
    Material Options:
    Aluminum
    Style Options:
    Surface Mount
    Product Type:
    Frame & Chassis
    Ready To Ship:
    Yes
    Now: $118.99
    Was: $169.99
    Qty in Cart: 0
    Price:
    Now: $118.99
    Was: $169.99
    Subtotal:
  • 304 Stainless Steel 12 Inch Sectionalized Deck Plate Filler Section

    304 Stainless Steel 12 Inch Sectionalized Deck Plate Filler Section

    IOWA CUSTOMS

    $268.99
    12 Inch 304 Stainless Steel Sectionalized Deck Plate Filler SectionDress up your truck with this stainless steel 12-inch plate filler. Part of Iowa Customs patented sectional deck place system, this...
    09-050300048
    SKU:
    09-050300048
    Truck Class:
    Universal
    Make:
    Universal Items
    Material Options:
    Stainless Steel
    Style Options:
    Surface Mount
    Product Type:
    Frame & Chassis
    $268.99
    Qty in Cart: 0
    Price:
    $268.99
    Subtotal:
  • Smooth Aluminum On-Top Air Line Box Deck Plate W/ Trailer Air, 2 7-Way Hookups, 2 - 4 Inch Light Holes

    Smooth Aluminum On-Top Air Line Box Deck Plate W/ Trailer Air, 2 7-Way Hookups, 2 - 4 Inch Light Holes

    IOWA CUSTOMS

    $459.99
    On-Top Air Line Box Deck Plate W/ Trailer Air, 2 7-Way Hookups & 2 - 4 Inch Light Holes* High Quality Deck Plate Accessories* Made Of Smooth Aluminum* On-Top Airline Box * With Trailer Air Two 7-Way...
    09-050300047
    SKU:
    09-050300047
    Truck Class:
    Universal
    Make:
    Universal Items
    Material Options:
    Aluminum
    Style Options:
    Surface Mount
    Finish Options:
    Smooth
    Product Type:
    Frame & Chassis
    $459.99
    Qty in Cart: 0
    Price:
    $459.99
    Subtotal:
  • 304 Stainless Steel On-Top Air Line Box Deck Plate W/ Trailer Air, 2 7-Way Hookups, 2 - 4 Inch Light Holes

    304 Stainless Steel On-Top Air Line Box Deck Plate W/ Trailer Air, 2 7-Way Hookups, 2 - 4 Inch Light Holes

    IOWA CUSTOMS

    $512.99
    On-Top Air Line Box Deck Plate W/ Trailer Air, 2 7-Way Hookups & 2 - 4 Inch Light Holes* High Quality Deck Plate Accessories* Made Of Polished Stainless Steel* On-Top Airline Box * With Trailer Air...
    09-050300046
    SKU:
    09-050300046
    Truck Class:
    Universal
    Make:
    Universal Items
    Finish Options:
    Polished
    Style Options:
    Surface Mount
    Material Options:
    Stainless Steel
    Product Type:
    Frame & Chassis
    $512.99
    Qty in Cart: 0
    Price:
    $512.99
    Subtotal:
  • Smooth Aluminum On-Top Air Line Box Deck Plate W/ Trailer Air, 7-Way Hookup, 2 - 4 Inch Light Holes

    Smooth Aluminum On-Top Air Line Box Deck Plate W/ Trailer Air, 7-Way Hookup, 2 - 4 Inch Light Holes

    IOWA CUSTOMS

    $459.99
    On-Top Air Line Box Deck Plate W/ Trailer Air, 7-Way Hookup & 2 - 4 Inch Light Holes* High Quality Sectionalized Deck Plate* Made Of Smooth Aluminum* On-Top Airline Box * With Trailer Air * One 7-Way...
    09-050300045
    SKU:
    09-050300045
    Truck Class:
    Universal
    Make:
    Universal Items
    Material Options:
    Aluminum
    Finish Options:
    Smooth
    Style Options:
    Surface Mount
    Product Type:
    Frame & Chassis
    $459.99
    Qty in Cart: 0
    Price:
    $459.99
    Subtotal:
  • 304 Stainless Steel On-Top Air Line Box Deck Plate W/ Trailer Air, 7-Way Hookup, 2 - 4 Inch Light Holes

    304 Stainless Steel On-Top Air Line Box Deck Plate W/ Trailer Air, 7-Way Hookup, 2 - 4 Inch Light Holes

    IOWA CUSTOMS

    $512.99
    On-Top Air Line Box Deck Plate W/ Trailer Air, 7-Way Hookup & 2 - 4 Inch Light Holes* High Quality Deck Plate Accessories* Made Of Polished Stainless Steel* On-Top Airline Box * With Trailer Air One...
    09-050300044
    SKU:
    09-050300044
    Truck Class:
    Universal
    Make:
    Universal Items
    Finish Options:
    Polished
    Style Options:
    Surface Mount
    Material Options:
    Stainless Steel
    Product Type:
    Frame & Chassis
    $512.99
    Qty in Cart: 0
    Price:
    $512.99
    Subtotal:
  • Paintable Stainless On-Top Air Line Box Sectionalized Deck Plate W/ Trailer Air, 7-Way, Hydraulic Hookups

    Paintable Stainless On-Top Air Line Box Sectionalized Deck Plate W/ Trailer Air, 7-Way, Hydraulic Hookups

    IOWA CUSTOMS

    $459.99
    On-Top Air Line Box Sectionalized Deck Plate W/ Trailer Air, 7-Way & Hydraulic HookupsThis Deck Plate Accessory is made from paintable stainless steel, so you can customize it to match your style. It...
    09-050300043
    SKU:
    09-050300043
    Truck Class:
    Universal
    Make:
    Universal Items
    Style Options:
    Surface Mount
    Product Type:
    Frame & Chassis
    Finish Options:
    Paintable
    Material Options:
    Stainless Steel
    Location:
    Made In USA
    $459.99
    Qty in Cart: 0
    Price:
    $459.99
    Subtotal:
  • On-Top Air Line Box 304 Stainless Steel W/ Holes For Trailer Air, 7-Way, Hydraulic Hookups

    On-Top Air Line Box 304 Stainless Steel W/ Holes For Trailer Air, 7-Way, Hydraulic Hookups

    IOWA CUSTOMS

    $514.99
    On-Top Air Line Box W/ Trailer Air, 7-Way & Hydraulic Hookups* High Quality On-Top Airline Box * Made Of 304 Stainless Steel* #8 Polished Finish* Includes:   - Trailer Air   - Hydraulic Hook-Ups  -...
    09-050300042
    SKU:
    09-050300042
    Truck Class:
    Universal
    Make:
    Universal Items
    Finish Options:
    Polished
    Style Options:
    Surface Mount
    Material Options:
    Stainless Steel
    Product Type:
    Frame & Chassis
    Location:
    Made In USA
    Ready To Ship:
    Yes
    $514.99
    Qty in Cart: 0
    Price:
    $514.99
    Subtotal:
  • Smooth Aluminum On-Top Air Line Box Sectionalized Deck Plate W/ Trailer Air, 2 7-Way Hookups

    Smooth Aluminum On-Top Air Line Box Sectionalized Deck Plate W/ Trailer Air, 2 7-Way Hookups

    IOWA CUSTOMS

    $459.99
    On-Top Air Line Box Sectionalized Deck Plate W/ Trailer Air & 2 7-Way Hookups* High Quality Deck Plate Accessories* Made Of Smooth Aluminum* On-Top Airline Box * With Trailer Air And Two 7-Ways *...
    09-050300041
    SKU:
    09-050300041
    Truck Class:
    Universal
    Make:
    Universal Items
    Material Options:
    Aluminum
    Finish Options:
    Smooth
    Style Options:
    Surface Mount
    Product Type:
    Frame & Chassis
    $459.99
    Qty in Cart: 0
    Price:
    $459.99
    Subtotal:
  • 304 Stainless Steel On-Top Air Line Box Sectionalized Deck Plate W/ Trailer Air, 2 7-Way Hookups

    304 Stainless Steel On-Top Air Line Box Sectionalized Deck Plate W/ Trailer Air, 2 7-Way Hookups

    IOWA CUSTOMS

    $577.99
    On-Top Air Line Box Sectionalized Deck Plate W/ Trailer Air & 2 7-Way Hookups* High Quality Deck Plate Accessories* Made Of Polished Stainless Steel* On-Top Airline Box * With Trailer Air And Two...
    09-050300040
    SKU:
    09-050300040
    Truck Class:
    Universal
    Make:
    Universal Items
    Finish Options:
    Polished
    Style Options:
    Surface Mount
    Material Options:
    Stainless Steel
    Product Type:
    Frame & Chassis
    $577.99
    Qty in Cart: 0
    Price:
    $577.99
    Subtotal:
  • Smooth Aluminum On-Top Air Line Box Deck Plate W/ Trailer Air, 7-Way Hookups

    Smooth Aluminum On-Top Air Line Box Deck Plate W/ Trailer Air, 7-Way Hookups

    IOWA CUSTOMS

    $459.99
    On-Top Air Line Box Deck Plate W/ Trailer Air & 7-Way Hookups* High Quality Deck Plate Accessories* Made Of Smooth Aluminum* On-Top Airline Box * With Trailer Air And One 7-Way Hook Ups* Made In USA*...
    09-050300039
    SKU:
    09-050300039
    Truck Class:
    Universal
    Make:
    Universal Items
    Material Options:
    Aluminum
    Style Options:
    Surface Mount
    Finish Options:
    Smooth
    Product Type:
    Frame & Chassis
    $459.99
    Qty in Cart: 0
    Price:
    $459.99
    Subtotal:
  • 304 Stainless Steel On-Top Air Line Box Deck Plate W/ Trailer Air, 7-Way Hookups

    304 Stainless Steel On-Top Air Line Box Deck Plate W/ Trailer Air, 7-Way Hookups

    IOWA CUSTOMS

    $563.99
    On-Top Air Line Box Deck Plate W/ Trailer Air & 7-Way Hookups* High Quality Deck Plate Accessories* Made Of Polished Stainless Steel* On-Top Airline Box * With Trailer Air And One 7-Way Hook Ups*...
    09-050300038
    SKU:
    09-050300038
    Truck Class:
    Universal
    Make:
    Universal Items
    Finish Options:
    Polished
    Style Options:
    Surface Mount
    Material Options:
    Stainless Steel
    Product Type:
    Frame & Chassis
    $563.99
    Qty in Cart: 0
    Price:
    $563.99
    Subtotal:
  • Smooth Aluminum On-Top Air Line Box Deck Plate W/ Trailer Air, 7-Way, 4/6-Way Hookups

    Smooth Aluminum On-Top Air Line Box Deck Plate W/ Trailer Air, 7-Way, 4/6-Way Hookups

    IOWA CUSTOMS

    $459.99
    On-Top Air Line Box Deck Plate W/ Trailer Air, 7-Way & 4/6-Way Hookups* High Quality Deck Plate Accessories* Made Of Smooth Aluminum* On-Top Airline Box * With Trailer Air * One 7-Way And One 4/6 Way...
    09-050300037
    SKU:
    09-050300037
    Truck Class:
    Universal
    Make:
    Universal Items
    Material Options:
    Aluminum
    Finish Options:
    Smooth
    Style Options:
    Surface Mount
    Product Type:
    Frame & Chassis
    $459.99
    Qty in Cart: 0
    Price:
    $459.99
    Subtotal:
  • 304 Stainless Steel On-Top Air Line Box Deck Plate W/ Trailer Air, 7-Way, 4/6-Way Hookups

    304 Stainless Steel On-Top Air Line Box Deck Plate W/ Trailer Air, 7-Way, 4/6-Way Hookups

    IOWA CUSTOMS

    $512.99
    On-Top Air Line Box Deck Plate W/ Trailer Air, 7-Way & 4/6-Way Hookups* High Quality Deck Plate Accessories* Made Of Polished Stainless Steel* On-Top Airline Box * With Trailer Air One 7-Way And One...
    09-050300036
    SKU:
    09-050300036
    Truck Class:
    Universal
    Make:
    Universal Items
    Finish Options:
    Polished
    Style Options:
    Surface Mount
    Material Options:
    Stainless Steel
    Product Type:
    Frame & Chassis
    $512.99
    Qty in Cart: 0
    Price:
    $512.99
    Subtotal:
  • Paintable SS Blank On-Top Air Line Box,

    Paintable SS Blank On-Top Air Line Box,

    IOWA CUSTOMS

    $339.99
    Paintable Stainless Steel On-Top Air Line Box With No Holes* High Quality Deck Plate Accessories* Made Of Stainless Steel* Paintable Finish* On-Top Airline Box * Blank* No Holes* Made In USA* Sold...
    09-050300035
    SKU:
    09-050300035
    Truck Class:
    Universal
    Make:
    Universal Items
    Style Options:
    Surface Mount
    Product Type:
    Frame & Chassis
    Material Options:
    Stainless Steel
    Finish Options:
    Paintable
    Ready To Ship:
    Yes
    $339.99
    Qty in Cart: 0
    Price:
    $339.99
    Subtotal:
  • Polished 304 Stainless Steel Blank On-Top Air Line Box Deck Plate Accessory

    Polished 304 Stainless Steel Blank On-Top Air Line Box Deck Plate Accessory

    IOWA CUSTOMS

    $490.99
    Blank Polished 304 Stainless Steel On-Top Air Line Box Deck Plate Accessory* High Quality Deck Plate Accessories* Made Of Polished Stainless Steel* On-Top Airline Box * Blank* No Holes * Made In USA*...
    09-050300034
    SKU:
    09-050300034
    Truck Class:
    Universal
    Make:
    Universal Items
    Finish Options:
    Polished
    Style Options:
    Surface Mount
    Material Options:
    Stainless Steel
    Product Type:
    Frame & Chassis
    $490.99
    Qty in Cart: 0
    Price:
    $490.99
    Subtotal:
  • Aluminum 18 Inch Recessed Air Line Box Sectionalized Deck Plate W/ Trailer Air, 7-Way, 4/6-Way Hookups

    Aluminum 18 Inch Recessed Air Line Box Sectionalized Deck Plate W/ Trailer Air, 7-Way, 4/6-Way Hookups

    IOWA CUSTOMS

    $490.99
    18 Inch Smooth Aluminum Recessed Air Line Box Sectionalized Deck Plate W/ Trailer Air, 7-Way, 4/6-Way HookupsOrganize connectors on the back of your truck with this 18 inch recessed air line box by...
    09-050300031
    SKU:
    09-050300031
    Truck Class:
    Universal
    Make:
    Universal Items
    Finish Options:
    Smooth
    Style Options:
    Flush Mount
    Material Options:
    Aluminum
    Product Type:
    Frame & Chassis
    $490.99
    Qty in Cart: 0
    Price:
    $490.99
    Subtotal:
  • 304 SS 18 Inch Recessed Air Line Box Sectionalized Deck Plate W/ 2 Air, One 7-Way & One 4 or 6 Way Cutouts

    304 SS 18 Inch Recessed Air Line Box Sectionalized Deck Plate W/ 2 Air, One 7-Way & One 4 or 6 Way Cutouts

    IOWA CUSTOMS

    $655.99
    18 Inch 304 Stainless Steel Recessed Air Line Box Sectionalized Deck Plate W/ 2 Air, One 7-Way & One 4 Or 6-Way CutoutsOrganize connectors on the back of your truck with this 18 inch recessed air...
    09-050300030
    SKU:
    09-050300030
    Truck Class:
    Universal
    Make:
    Universal Items
    Material Options:
    Stainless Steel
    Style Options:
    Flush Mount
    Product Type:
    Frame & Chassis
    $655.99
    Qty in Cart: 0
    Price:
    $655.99
    Subtotal:
  • 304 SS 18 Inch Recessed Air Line Box Sectionalized Deck Plate W/ 2 Air & Two 7-Way Cutouts

    304 SS 18 Inch Recessed Air Line Box Sectionalized Deck Plate W/ 2 Air & Two 7-Way Cutouts

    IOWA CUSTOMS

    $655.99
    18 Inch 304 Stainless Steel Recessed Air Line Box Sectionalized Deck Plate W/ 2 Air & Two 7-Way CutoutsOrganize connectors on the back of your truck with this 18 inch recessed air line box by Iowa...
    09-050300029
    SKU:
    09-050300029
    Length Options:
    18 Inch
    Location:
    Made In USA
    Truck Class:
    Universal
    Material Options:
    Stainless Steel
    Make:
    Universal Items
    Style Options:
    Flush Mount
    Product Type:
    Frame & Chassis
    $655.99
    Qty in Cart: 0
    Price:
    $655.99
    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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