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Peterbilt 357/378 Parts

Find the best Peterbilt 378 aftermarket parts in the business here at 4 State. The Peterbilt 378 semi truck represents all of the characteristics of the Peterbilt brand, and was a popular model with similar features to the Peterbilt 379. Pete truck models are a brand of choice for experienced truckers who need dependable semi trucks. 4 State Trucks has all the semi truck parts and accessories you need to make your Pete 378 stand out to showcase your unique personality. Whether you need aftermarket bumpers, exhaust, or fuel tanks, we've got you covered. Hit the open road in style and comfort with the best custom gear for your Peterbilt heavy duty truck or 18 wheeler.
  • Product
  • Qty in Cart
  • Quantity
  • Price
  • Subtotal
  • Stainless Steel U Shaped Flap Weight

    Stainless Steel U Shaped Flap Weight

    ROADWORKS

    $70.99
    24 Inch U Shape Flap Weight* High Quality Flap Weight* Made Of 430 Stainless Steel* U Shaped * With Brackets * 24 Inches* Made In USA* Sold As Pair * Warranty On Flap Weight Against Defects In...
    09-0507082
    SKU:
    09-0507082
    Truck Class:
    Universal
    Location:
    Made In USA
    Width Options:
    24 Inch
    Material Options:
    Stainless Steel
    Make:
    Universal Items
    Product Type:
    Frame & Chassis
    $70.99
    Qty in Cart: 0
    Price:
    $70.99
    Subtotal:
  • FREE SHIPPING OVER $249
    White 4 State Trucks Plastic Mud Flap 24 X 30 Inch

    White 4 State Trucks Plastic Mud Flap 24 X 30 Inch

    4 STATE TRUCKS

    $35.36
    White 4 State Trucks Mud FlapReduce water spray in wet conditions with this thick 4 State Truck Logo rubber mud flap. It is sold individually and attaches behind your tire. The mud flap measures...
    09-0507073
    SKU:
    09-0507073
    Truck Class:
    Universal
    Height Options:
    30 Inch
    Width Options:
    24 Inch
    Material Options:
    Plastic/Poly
    Make:
    Universal Items
    Color:
    White
    Product Type:
    Mud Flaps
    Ready To Ship:
    Yes
    $35.36
    Qty in Cart: 0
    Price:
    $35.36
    Subtotal:
  • FREE SHIPPING OVER $249
    6 X 24 Inch Stainless Steel Shark Teeth Bottom Mud Flap Weight W/ Backing Plate

    6 X 24 Inch Stainless Steel Shark Teeth Bottom Mud Flap Weight W/ Backing Plate

    GRAND GENERAL

    $57.99
    14 Gauge Stainless Steel Bottom Mud Flap Plate - Shark Teeth Style* High Quality Mud Flap Plate* Shark Teeth Bottom* 14 GA Stainless Steel* Dimensions  - 24 Inch Width  - 6 Inch Height* 6 Hole Cutout...
    09-0507061
    SKU:
    09-0507061
    Truck Class:
    Universal
    Height Options:
    6 Inch
    Width Options:
    24 Inch
    Material Options:
    Stainless Steel
    Size Options:
    14 Gauge
    Make:
    Universal Items
    Product Type:
    Mud Flaps
    $57.99
    Qty in Cart: 0
    Price:
    $57.99
    Subtotal:
  • SS 5.5 X 24 Inch Flame Style Top Flap Weight

    SS 5.5 X 24 Inch Flame Style Top Flap Weight

    ROADWORKS

    $72.99
    Stainless Steel 5.5 X 24 Inch Flame Top Flap Weight* High Quality Mud Flap Weights* Made Of Stainless Steel* 24 Inch X 5.5 Inch* Flame Style * Made In USA* Sold In Pairs* Warranty On Flap Weight...
    09-0507056
    SKU:
    09-0507056
    Width Options:
    24 Inch
    Location:
    Made In USA
    Truck Class:
    Universal
    Material Options:
    Stainless Steel
    Make:
    Universal Items
    Product Type:
    Mud Flaps
    $72.99
    Qty in Cart: 0
    Price:
    $72.99
    Subtotal:
  • FREE SHIPPING OVER $249
    4 X 24 Inch 430 Stainless Steel Bottom Mud Flap Weights by Turnpike Truck Trim

    4 X 24 Inch 430 Stainless Steel Bottom Mud Flap Weights by Turnpike Truck Trim

    TURNPIKE TRUCK TRIM

    $40.79
    430 SS 4 X 24 Inch Bottom Flap Weights With Hardware by Turnpike Truck TrimKeep The Mud Flaps On Your Truck In Great Working Condition And From Flapping Wildly In The Wind With Stainless Steel...
    09-0507054
    SKU:
    09-0507054
    Height Options:
    4 Inch
    Width Options:
    24 Inch
    Truck Class:
    Universal
    Material Options:
    Stainless Steel
    Make:
    Universal Items
    Product Type:
    Frame & Chassis
    Ready To Ship:
    Yes
    $40.79
    Qty in Cart: 0
    Price:
    $40.79
    Subtotal:
  • FREE SHIPPING OVER $249
    24 Inch Stainless Steel Mud Flap Weights W/ Bolted Angled Bottom by TPHD

    24 Inch Stainless Steel Mud Flap Weights W/ Bolted Angled Bottom by TPHD

    TPHD

    $47.37
    4 X 24 Inch Stainless Steel Bottom Flap WeightsKeep your mud flaps from curling up with this pair of shiny stainless steel weights with backing plates. They easily bolt to the bottom of 24 inch mud...
    09-0507053
    SKU:
    09-0507053
    Height Options:
    4 Inch
    Truck Class:
    Heavy Duty
    Material Options:
    Stainless Steel
    Make:
    Universal Items
    Width Options:
    24 Inch
    Finish Options:
    Polished
    Product Type:
    Mud Flaps
    Ready To Ship:
    Yes
    $47.37
    Qty in Cart: 0
    Price:
    $47.37
    Subtotal:
  • FREE SHIPPING OVER $249
    Turnpike Truck Trim SS 24 Inch Louvered Flap Weights

    Turnpike Truck Trim SS 24 Inch Louvered Flap Weights

    TURNPIKE TRUCK TRIM

    $104.99
    Stainless Steel Louvered Flap WeightsGet your mud flaps outfitted with these stainless steel weights, measuring in at a solid 24 inches. Made right here in the USA, these weights come with handy...
    09-0507052
    SKU:
    09-0507052
    Truck Class:
    Universal
    Width Options:
    24 Inch
    Style Options:
    Louvered
    Material Options:
    Stainless Steel
    Make:
    Universal Items
    Product Type:
    Frame & Chassis
    Ready To Ship:
    Yes
    $104.99
    Qty in Cart: 0
    Price:
    $104.99
    Subtotal:
  • FREE SHIPPING OVER $249
    CSM 3.25 X 18 Inch Stainless Steel Bottom Mud Flap Weight

    CSM 3.25 X 18 Inch Stainless Steel Bottom Mud Flap Weight

    CHROME SHOP MAFIA

    $38.86
    SS 2.75 X 18 Inch Bottom Mud Flap Weights By Chrome Shop MafiaKeep the mud flaps on your truck in great working condition and from flapping wildly in the wind with stainless steel weights by Chrome...
    09-0507051
    SKU:
    09-0507051
    Width Options:
    18 Inch
    Truck Class:
    Universal
    Location:
    Made In USA
    Material Options:
    Stainless Steel
    Make:
    Universal Items
    Height Options:
    3 1/2 Inch
    Product Type:
    Mud Flaps
    Ready To Ship:
    Yes
    $38.86
    Qty in Cart: 0
    Price:
    $38.86
    Subtotal:
  • FREE SHIPPING OVER $249
    Stainless Steel Mud Flap Hanger End Plug

    Stainless Steel Mud Flap Hanger End Plug

    UNITED PACIFIC

    $9.94
    SS Mud Flap Hanger End PlugKeep dirt and debris out of your mud flap hangers with these snap in plugs by United Pacific. Sold in pairs, they are made of stainless steel and measure 2 inches each.*...
    09-0507045
    SKU:
    09-0507045
    Truck Class:
    Universal
    Material Options:
    Stainless Steel
    Make:
    Universal Items
    Product Type:
    Mud Flaps
    Ready To Ship:
    Yes
    $9.94
    Qty in Cart: 0
    Price:
    $9.94
    Subtotal:
  • FREE SHIPPING OVER $249
    24 Inch Angled Top Flap Plate W/ Reflector

    24 Inch Angled Top Flap Plate W/ Reflector

    UNITED PACIFIC

    $27.10
    Angled Conspicuity Reflector Plate* High Quality Reflector Plate* Made Of Aluminum* 24 Inch Width* Angled At 45 Degrees* For Angled Mud Flap Hanger* Sold As Pair* Warranty On Reflector Plate Against...
    09-0507035
    SKU:
    09-0507035
    Truck Class:
    Universal
    Width Options:
    24 Inch
    Style Options:
    Angled
    Material Options:
    Aluminum
    Make:
    Universal Items
    Product Type:
    Mud Flaps
    Ready To Ship:
    Yes
    $27.10
    Qty in Cart: 0
    Price:
    $27.10
    Subtotal:
  • FREE SHIPPING OVER $249
    24 Inch Top Flap Weight W/ Reflector

    24 Inch Top Flap Weight W/ Reflector

    UNITED PACIFIC

    $24.73
    Straight Conspicuity Reflector PlateHelp keep your mud flaps in place with this 24-inch reflector style top flap weight. Its durable aluminum construction ensures a secure fit, adding a touch of...
    09-0507034
    SKU:
    09-0507034
    Width Options:
    24 Inch
    Truck Class:
    Universal
    Material Options:
    Aluminum
    Make:
    Universal Items
    Product Type:
    Mud Flaps
    Ready To Ship:
    Yes
    $24.73
    Qty in Cart: 0
    Price:
    $24.73
    Subtotal:
  • FREE SHIPPING OVER $249
    16.25 Inch SS Mud Flap Anti-Sail Plates Plain

    16.25 Inch SS Mud Flap Anti-Sail Plates Plain

    UNITED PACIFIC

    $98.99
    Stainless Steel 16.25 Inch Tall Anti-Sail Mud Flap PlatesKeep your rear mud flaps down with these anti-sail panels by United Pacific. They are made of stainless steel and attach to the top of most...
    09-0507027
    SKU:
    09-0507027
    Truck Class:
    Universal
    Material Options:
    Stainless Steel
    Make:
    Universal Items
    Width Options:
    12 Inch
    Product Type:
    Mud Flaps
    Height Options:
    16 Inch
    Ready To Ship:
    Yes
    $98.99
    Qty in Cart: 0
    Price:
    $98.99
    Subtotal:
  • FREE SHIPPING OVER $249
    BESTfit 24 X 21 Inch Chrome Anti-Sail Bracket For Mud Flaps

    BESTfit 24 X 21 Inch Chrome Anti-Sail Bracket For Mud Flaps

    BESTFIT TRUCK PARTS

    $11.21
    BESTfit Anti-Sail Bracket Chrome For 24 Inch Wide Mud FlapsReduce wear and tear on your mud flaps by keeping them straight and flat when driving with this chrome-finished anti-sail bracket. It fits...
    09-0507013
    SKU:
    09-0507013
    Truck Class:
    Universal
    Material Options:
    Stainless Steel
    Make:
    Universal Items
    Finish Options:
    Chrome-Plated
    Product Type:
    Mud Flaps
    Height Options:
    24 Inch
    Width Options:
    21 Inch
    Ready To Ship:
    Yes
    $11.21
    Qty in Cart: 0
    Price:
    $11.21
    Subtotal:
  • FREE SHIPPING OVER $249
    4 X 20 Inch Chrome Bottom Mud Flap Weight W/ 3 Bolt Thru Studs

    4 X 20 Inch Chrome Bottom Mud Flap Weight W/ 3 Bolt Thru Studs

    UNITED PACIFIC

    $17.81
    Chrome 4X20 Inch Bottom Mud Flap WeightKeep the mud flaps on your truck in great working condition and from flapping wildly in the wind with this chrome plated weight. It mounts to the bottom of a 20...
    09-0507011
    SKU:
    09-0507011
    Truck Class:
    Universal
    Width Options:
    20 Inch
    Material Options:
    Stainless Steel
    Make:
    Universal Items
    Finish Options:
    Chrome-Plated
    Height Options:
    4 Inch
    Product Type:
    Mud Flaps
    Ready To Ship:
    Yes
    $17.81
    Qty in Cart: 0
    Price:
    $17.81
    Subtotal:
  • FREE SHIPPING OVER $249
    Stainless Steel Top Mud Flap Plate W/ 19 LED 17 Inch Light Bar - Red LED / Red Lens

    Stainless Steel Top Mud Flap Plate W/ 19 LED 17 Inch Light Bar - Red LED / Red Lens

    UNITED PACIFIC

    $57.99
    SS Top Mud Flap Plate W/ 19 Red LED 17 Inch Light Bar* High Quality Top Mud Flap Plate* Made Of Stainless Steel* With 19 LED 17 Inch Light Bar* Red LED/Red Lens* Stainless Steel Top Mud Flap Bracket...
    09-050700171
    SKU:
    09-050700171
    Truck Class:
    Universal
    Light Options:
    With Lights
    Color:
    Red
    Material Options:
    Stainless Steel
    Make:
    Universal Items
    Width Options:
    17 Inch
    Product Type:
    Mud Flaps
    $57.99
    Qty in Cart: 0
    Price:
    $57.99
    Subtotal:
  • Stainless Steel Top Mud Flap Plate W/ 19 LED 17 Inch Light Bar & Chrome Bezel - Red LED / Red Lens

    Stainless Steel Top Mud Flap Plate W/ 19 LED 17 Inch Light Bar & Chrome Bezel - Red LED / Red Lens

    UNITED PACIFIC

    $66.99
    Stainless Steel Top Mud Flap Plate W/ 19 LED Light Bar* High Quality Top Mud Flap Plate* With Chrome Bezel* Made Of Stainless Steel* With 19 LED 17 Inch Light Bar * Red LED/Red Lens* Stainless Steel...
    09-050700170
    SKU:
    09-050700170
    Truck Class:
    Universal
    Light Options:
    With Lights
    Color:
    Red
    Material Options:
    Stainless Steel
    Make:
    Universal Items
    Width Options:
    17 Inch
    Finish Options:
    Chrome-Plated
    Product Type:
    Mud Flaps
    $66.99
    Qty in Cart: 0
    Price:
    $66.99
    Subtotal:
  • FREE SHIPPING OVER $249
    Chrome Top Mud Flap Plate W/ 19 LED 17 Inch Light Bar - Red LED/ Red Lens

    Chrome Top Mud Flap Plate W/ 19 LED 17 Inch Light Bar - Red LED/ Red Lens

    UNITED PACIFIC

    $39.01
    Stud Mounted Mud Flap Plate W/ 17 Inch LED Light Bar* High Quality Top Mud Flap Plate* Made Of Chrome Plated Steel * With 19 LED 17 Inch Light Bar* Red LED/Red Lens* Stud Mounted* Chrome Top Mud Flap...
    09-050700169
    SKU:
    09-050700169
    Light Options:
    With Lights
    Truck Class:
    Universal
    Color:
    Red
    Material Options:
    Steel
    Make:
    Universal Items
    Finish Options:
    Chrome-Plated
    Width Options:
    17 Inch
    Product Type:
    Mud Flaps
    $39.01
    Qty in Cart: 0
    Price:
    $39.01
    Subtotal:
  • FREE SHIPPING OVER $249
    Chrome Top Mud Flap Plate With 19 LED 17 Inch Light Bar & Bezel - Red LED/Red Lens

    Chrome Top Mud Flap Plate With 19 LED 17 Inch Light Bar & Bezel - Red LED/Red Lens

    UNITED PACIFIC

    $49.33
    Chrome Top Plate W/ 19 LED 17 Inch Light Bar & Stud Mount* High Quality Top Mud Flap Plate * With Bezel* Made Of Chrome Plated Steel * With 19 LED 17 Inch Light Bar* Red LED/Red Lens* Stud Mounted*...
    09-050700168
    SKU:
    09-050700168
    Light Options:
    With Lights
    Truck Class:
    Universal
    Color:
    Red
    Material Options:
    Steel
    Make:
    Universal Items
    Finish Options:
    Chrome-Plated
    Width Options:
    17 Inch
    Product Type:
    Mud Flaps
    $49.33
    Qty in Cart: 0
    Price:
    $49.33
    Subtotal:
  • FREE SHIPPING OVER $249
    TPHD 24 X 30 Inch Aerodynamic Mud Flap

    TPHD 24 X 30 Inch Aerodynamic Mud Flap

    TURNPIKE TRUCK TRIM

    $62.99
    Nylon Polymer 24 X 30 In. Impact Resistant Splash Guard* High Quality Splash Guard* 24 X 30 Inch* Eco Aerodynamic * Impact Resistant Nylon Polymer* Molded Wing-Shaped Channels Move Air And Water...
    09-050700167
    SKU:
    09-050700167
    Width Options:
    24 Inch
    Truck Class:
    Universal
    Height Options:
    36 Inch
    Material Options:
    Plastic/Poly
    Make:
    Universal Items
    Product Type:
    Frame & Chassis
    $62.99
    Qty in Cart: 0
    Price:
    $62.99
    Subtotal:
  • FREE SHIPPING OVER $249
    Stainless Steel Top Mud Flap Plate W/ Bolt Thru Mounting Stud

    Stainless Steel Top Mud Flap Plate W/ Bolt Thru Mounting Stud

    UNITED PACIFIC

    $12.84
    SS Top Plate W/ Bolt Thru Mounting For Mud Flaps* High Quality Top Mud Flap Plate* Made Of 430 Stainless Steel* Includes:  - (1) Top Mud Flap Plate  - (4) Bolt Through Mounting Studs  - Mounting...
    09-050700166
    SKU:
    09-050700166
    Truck Class:
    Universal
    Material Options:
    Stainless Steel
    Make:
    Universal Items
    Product Type:
    Mud Flaps
    Ready To Ship:
    Yes
    $12.84
    Qty in Cart: 0
    Price:
    $12.84
    Subtotal:
  • Total: items /

Adding your products to cart

The Peterbilt 357 and 378 are known for their no-nonsense durability and old-school style. Whether you’re hauling heavy loads or running construction jobs, these workhorses are built to last—and we’re here to help you keep them in top shape.

Why Choose Aftermarket Peterbilt 357/378 Truck Parts?

- Engineered for your model: Every part is made to fit and function with your 357 or 378—so you can skip the guesswork and get back to work. - Performance you can count on: Keep your truck running strong with engine, transmission, suspension, fiberglass Pete 357/378 hood shells, LED headlights, and cab lighting accessories designed to turn heads. - Trusted brands, proven quality: We only carry parts from manufacturers we trust, so you know you're getting durable, road-tested gear. - Quick shipping, expert help: Get your parts fast and reach out to our team if you need help finding the right fit—we’ve got your back.

Shop the Perfect Aftermarket Accessories for Peterbilt 357/378 Trucks


Whether you're restoring a classic or keeping your work truck rolling, our Peterbilt 357 and 378 parts are built to match the strength and legacy of these iconic models. We stock a wide selection of aftermarket and replacement parts designed specifically for Peterbilt 357 and 378 models. From critical mechanical components to sleek interior cab accessory upgrades, we’ve got what you need to maintain, repair, or customize your rig. Explore our full selection and get the parts you need to keep your rig road-ready.

Frequently Asked Questions About Peterbilt 357/378 Parts

What years and models are compatible with Peterbilt 357/378 parts?

Most aftermarket parts for Peterbilt 357/378 trucks are designed to fit models from 1987 through 2007. However, there are important differences between early models (1987-1999) and later models (2000-2007), particularly in hood mounting points and grille configurations. Always verify the specific year range listed for each part, as some components like bumpers and fenders may have changed mounting hole patterns after the 2000 model year update.

Are aftermarket bumpers as durable as OEM Peterbilt bumpers?

Quality aftermarket bumpers are typically made from 16-gauge steel (same as OEM) and feature triple chrome plating or powder coating for corrosion resistance. The main differences you'll find are in the finishing details and fitment precision. While a well-made aftermarket bumper can last just as long as OEM, pay attention to the warranty offered - reputable manufacturers typically provide at least a 1-year warranty on chrome finish and 3-5 years on structural integrity.

What tools and modifications are needed to install replacement parts?

Most bolt-on parts like bumpers, grilles, and headlight assemblies require basic hand tools including socket sets (typically 1/2" to 3/4"), wrenches, and a drill with metal bits for any minor adjustments. Common installation challenges include slight drilling to align mounting holes (especially on pre-2000 models) and adjusting bumper brackets for proper fitment. Professional installation typically takes 2-4 hours for major components like bumpers or hoods.

What's the difference between chrome, stainless steel, and painted finishes?

Chrome-plated steel offers the brightest mirror finish but requires regular polishing and can pit in harsh climates. Stainless steel (usually 304 grade) provides excellent corrosion resistance with less maintenance but has a slightly duller appearance. Painted finishes are the most economical and can be color-matched to your truck, but may need repainting every 5-7 years depending on exposure. For winter driOEMg or coastal areas, stainless steel typically offers the best long-term value.

How do I ensure proper fitment when ordering hoods, fenders, or bumpers?

Start by confirming your exact model year and checking whether you have a standard or extended hood configuration. Measure key mounting points on your current parts before ordering - bumper width should be either 18" or 20" depending on your model. For hoods and fenders, verify whether you have the single-headlight or dual-headlight configuration. When in doubt, provide your OEM number when ordering to ensure compatibility, as some mid-year production changes aren't reflected in standard model year listings.


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