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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
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  • Price
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  • Oil Pump Replaces 3966840 For Cummins ISC 8.3L Engines

    Oil Pump Replaces 3966840 For Cummins ISC 8.3L Engines

    AFTERMARKET

    $140.99
    Cummins ISC 8.3L Engine Oil PumpThis premium Oil Pump for Cummins ISC 8.3L engines replaces part number 3966840 and is built for heavy-duty performance. Designed to maintain steady lubrication and...
    29-07200013
    SKU:
    29-07200013
    Product Type:
    Engine Parts
    Style Options:
    Cummins
    Make:
    Universal Items
    $140.99
    Qty in Cart: 0
    Price:
    $140.99
    Subtotal:
  • V-Band Clamp Kit Replaces 2871862

    V-Band Clamp Kit Replaces 2871862

    AUTOMANN USA

    $93.99
    Stainless Steel V-Band Clamp Kit W/ 13.375 Inch Nominal Diameter V- ClampThis high-performance V-Band Clamp Kit is engineered for Kenworth, Peterbilt, Freightliner, International, and Western Star...
    29-0809210
    SKU:
    29-0809210
    Material Options:
    Stainless Steel
    Product Type:
    Exhaust
    Make:
    Peterbilt
    Make:
    International
    Make:
    Kenworth
    Make:
    Freightliner
    Make:
    Western Star
    $93.99
    Qty in Cart: 0
    Price:
    $93.99
    Subtotal:
  • Oil Cooler Replaces 3957544, 3921558, 4713985AB, AP63467 For Cummins ISB 5.9L Engine

    Oil Cooler Replaces 3957544, 3921558, 4713985AB, AP63467 For Cummins ISB 5.9L Engine

    AFTERMARKET

    $164.99
    Oil Cooler W/ 7 PlatesThis high-performance Oil Cooler is the perfect replacement for Cummins ISB 5.9L engines. With 7 plated construction and fifteen precision-drilled holes-twelve at 0.340-inch and...
    29-07200005
    SKU:
    29-07200005
    Product Type:
    Engine Parts
    Style Options:
    Cummins
    Make:
    Universal Items
    $164.99
    Qty in Cart: 0
    Price:
    $164.99
    Subtotal:
  • 3.5 Inch Aluminized Steel Band Clamp Replaces A35AF, J000201

    3.5 Inch Aluminized Steel Band Clamp Replaces A35AF, J000201

    AUTOMANN USA

    $11.01
    3.5 Inch Aluminized Band ClampSecure your exhaust or piping system with this high-quality 3.5 Inch Aluminized Steel Band Clamp. Featuring pre-attached hardware and a Grade 8 M10 3/8-inch bolt, it...
    29-08000005
    SKU:
    29-08000005
    Diameter Options:
    3 1/2 Inch
    Product Type:
    Exhaust
    Width Options:
    1 1/4 Inch
    Material Options:
    Aluminized Steel
    Make:
    Universal Items
    $11.01
    Qty in Cart: 0
    Price:
    $11.01
    Subtotal:
  • EGR Pressure Differential Sensor Replaces 23531964 For Detroit Diesel 60 Series Engines

    EGR Pressure Differential Sensor Replaces 23531964 For Detroit Diesel 60 Series Engines

    AFTERMARKET

    $177.99
    EGR Pressure Differential Sensor- 3 PinMonitor exhaust gas pressure with confidence using this premium EGR Pressure Differential Sensor, replacement for Detroit Diesel 60 Series engines. Featuring 3...
    29-07100030
    SKU:
    29-07100030
    Product Type:
    Engine Parts
    Style Options:
    Detroit
    Make:
    Universal Items
    $177.99
    Qty in Cart: 0
    Price:
    $177.99
    Subtotal:
  • Oil Plug Replaces 9S-8004, 9S8004, 0995845 For Caterpillar C7 Engines

    Oil Plug Replaces 9S-8004, 9S8004, 0995845 For Caterpillar C7 Engines

    AUTOMANN USA

    $14.52
    0.684 X 0.500 Inch Oil Plug W/ 0.265 Inch A/F & 9/16 Inch - 18 ThreadMaintain your Caterpillar C7 engine with this premium Oil Plug. Its 0.265-inch A/F, 0.684-inch diameter, 0.500-inch length, and...
    29-07200010
    SKU:
    29-07200010
    Product Type:
    Engine Parts
    Style Options:
    Caterpillar
    Make:
    Universal Items
    $14.52
    Qty in Cart: 0
    Price:
    $14.52
    Subtotal:
  • Power Steering Reservoir Cover Replaces 3953866S, Q760236, Q760241, Q761939, NMCQ760236, 5839Q761939, Q761939FLG, FGQ761939

    Power Steering Reservoir Cover Replaces 3953866S, Q760236, Q760241, Q761939, NMCQ760236, 5839Q761939, Q761939FLG, FGQ761939

    AUTOMANN USA

    $24.17
    4.25 X 6.37 Inch Power Steering Reservoir CoverThis Power Steering Reservoir Cover is an essential replacement for maintaining smooth steering operation in your truck. It features exacting...
    29-07120013
    SKU:
    29-07120013
    Height Options:
    4 Inch
    Diameter Options:
    6 1/4 Inch
    Product Type:
    Engine Parts
    Make:
    Universal Items
    $24.17
    Qty in Cart: 0
    Price:
    $24.17
    Subtotal:
  • Oil Plug Replaces 168-2288, 1682288 For Caterpillar C7 Engines

    Oil Plug Replaces 168-2288, 1682288 For Caterpillar C7 Engines

    AUTOMANN USA

    $15.24
    0.953 Inch Oil Plug W/ 1.122 Inch A/F & M18 x 1.5 ThreadReplace worn or damaged plugs with this premium Oil Plug for Caterpillar C7 engines. With a 1.122-inch A/F, 0.953-inch length, and M18 x 1.5...
    29-07200009
    SKU:
    29-07200009
    Product Type:
    Engine Parts
    Style Options:
    Caterpillar
    Make:
    Universal Items
    $15.24
    Qty in Cart: 0
    Price:
    $15.24
    Subtotal:
  • EGR Pressure Differential Sensor Replaces P4050-5207-1, P405052071, ME555560 For Mitsubishi, Detroit Diesel

    EGR Pressure Differential Sensor Replaces P4050-5207-1, P405052071, ME555560 For Mitsubishi, Detroit Diesel

    AFTERMARKET

    $91.99
    2.78 Inch EGR Pressure Differential Sensor- 3 PinReliable performance and accurate EGR readings are ensured with this high-quality EGR Pressure Differential Sensor, replacement for Mitsubishi and...
    29-07100032
    SKU:
    29-07100032
    Style Options:
    Detroit
    Product Type:
    Engine Parts
    Length Options:
    2 3/4 Inch
    Make:
    Universal Items
    $91.99
    Qty in Cart: 0
    Price:
    $91.99
    Subtotal:
  • Power Steering Reservoir Cover Clamp Replaces NMCQ186425, Q186425

    Power Steering Reservoir Cover Clamp Replaces NMCQ186425, Q186425

    AUTOMANN USA

    $15.26
    5.75 Inch To 7.0 Inch ID Power Steering Reservoir Cover ClampReplace worn or damaged clamps with this durable Power Steering Reservoir Cover Clamp. Its adjustable 5.75 to 7.0-inch inner diameter and...
    29-07120015
    SKU:
    29-07120015
    Width Options:
    1/2 Inch
    Product Type:
    Engine Parts
    Make:
    Universal Items
    $15.26
    Qty in Cart: 0
    Price:
    $15.26
    Subtotal:
  • Belt Tensioner Assembly Replaces 1971873PE, 2143061PE, 2140648PE For PACCAR MX Engines

    Belt Tensioner Assembly Replaces 1971873PE, 2143061PE, 2140648PE For PACCAR MX Engines

    AUTOMANN USA

    $277.99
    2.952 X 1.84 Inch Belt Tensioner AssemblyOptimize your PACCAR MX engine performance with this high-quality Belt Tensioner Assembly. Featuring a pulley 1.840 inches wide and 2.952 inches in outer...
    29-07060177
    SKU:
    29-07060177
    Diameter Options:
    3 Inch
    Width Options:
    1 3/4 Inch
    Style Options:
    Paccar
    Product Type:
    Engine Parts
    Make:
    Universal Items
    $277.99
    Qty in Cart: 0
    Price:
    $277.99
    Subtotal:
  • Stainless Steel EGR Cooler Hardware Kit Replaces 20431718

    Stainless Steel EGR Cooler Hardware Kit Replaces 20431718

    AUTOMANN USA

    $688.99
    EGR Cooler Hardware KitReplace worn components with this stainless steel EGR Cooler Hardware Kit, engineered to replace 20431718. With two EGR pipes, five V-band clamps, gaskets, and full hardware,...
    29-07110008
    SKU:
    29-07110008
    Product Type:
    Engine Parts
    Material Options:
    Stainless Steel
    Style Options:
    Detroit
    Make:
    Universal Items
    $688.99
    Qty in Cart: 0
    Price:
    $688.99
    Subtotal:
  • Transmission Pressure Switch Replaces 29549658, 17KP489 For Allison Transmissions

    Transmission Pressure Switch Replaces 29549658, 17KP489 For Allison Transmissions

    AUTOMANN USA

    $33.30
    2.11 Inch Transmission Pressure Switch-2 PinAvoid costly transmission repairs with this high-performance Transmission Pressure Switch, engineered to replace 29549658 and 17KP489 for Allison...
    29-07100028
    SKU:
    29-07100028
    Style Options:
    2 Prong
    Product Type:
    Engine Parts
    Height Options:
    2 Inch
    Make:
    Universal Items
    $33.30
    Qty in Cart: 0
    Price:
    $33.30
    Subtotal:
  • 32 Inch Nylon 11 Blade Fan Blade Replaces 3809753C1, 3809753C2, 47354461001, 85138, 010023828 For Cummins ISX, Caterpillar C13 Engines

    32 Inch Nylon 11 Blade Fan Blade Replaces 3809753C1, 3809753C2, 47354461001, 85138, 010023828 For Cummins ISX, Caterpillar C13 Engines

    AUTOMANN USA

    $312.99
    32 Inch Fan Blade- 11 BladesProtect your engine from overheating with this durable 32 Inch Nylon 11 Blade Fan Blade, replacement for Cummins ISX and Caterpillar C13 trucks. Featuring 11 nylon blades,...
    29-07060178
    SKU:
    29-07060178
    Diameter Options:
    32 Inch
    Product Type:
    Engine Parts
    Material Options:
    Nylon
    Make:
    Universal Items
    $312.99
    Qty in Cart: 0
    Price:
    $312.99
    Subtotal:
  • Thermostat Replaces 2882757, 2952204, 3335550, 4318197, 4318947, 4973373, 34148 For Cummins

    Thermostat Replaces 2882757, 2952204, 3335550, 4318197, 4318947, 4973373, 34148 For Cummins

    AUTOMANN USA

    $47.09
    1.77 X 2.26 Inch ThermostatMaintain optimal engine operation with this high-performance 180 F Thermostat Cummins engines. Featuring precision coil and body dimensions, it delivers consistent cooling...
    29-071000031
    SKU:
    29-071000031
    Diameter Options:
    2 1/4 Inch
    Product Type:
    Engine Parts
    Style Options:
    Cummins
    Height Options:
    1 3/4 Inch
    Make:
    Universal Items
    $47.09
    Qty in Cart: 0
    Price:
    $47.09
    Subtotal:
  • Transmission Pressure Switch Replaces 29512944, 29542944, 29552364 For Allison Transmissions

    Transmission Pressure Switch Replaces 29512944, 29542944, 29552364 For Allison Transmissions

    AFTERMARKET

    $46.02
    2.98 X 4.70 Inch 2 Pin Transmission Pressure Switch W/ Inch CableMaximize the life of your transmission with this heavy-duty Transmission Pressure Switch, designed for Allison transmissions. With a...
    29-07100027
    SKU:
    29-07100027
    Product Type:
    Engine Parts
    Length Options:
    4 Inch
    Material Options:
    Steel
    Make:
    Universal Items
    $46.02
    Qty in Cart: 0
    Price:
    $46.02
    Subtotal:
  • 32 Inch Nylon 9 Blade Fan Blade Replaces 981813202, 991813202

    32 Inch Nylon 9 Blade Fan Blade Replaces 981813202, 991813202

    AFTERMARKET

    $224.99
    32 Inch Fan Blade- 9 BladesMaintain peak truck engine performance with this premium 32 Inch Nylon 9 Blade Fan Blade. Its 9 nylon blades, clockwise rotation, and 12 bolt holes provide efficient...
    29-07060184
    SKU:
    29-07060184
    Material Options:
    Nylon
    Diameter Options:
    32 Inch
    Product Type:
    Engine Parts
    Make:
    Universal Items
    $224.99
    Qty in Cart: 0
    Price:
    $224.99
    Subtotal:
  • Turbo Charger Mounting Kit For Caterpillar 3406E

    Turbo Charger Mounting Kit For Caterpillar 3406E

    POWER PLAY PRODUCTS

    $91.99
    Caterpillar 3406E Turbo Charger Mounting KitKeep your Caterpillar 3406E engine running efficiently with this high-performance Turbo Charger Mounting Kit. The kit includes all required gaskets and...
    29-070400083
    SKU:
    29-070400083
    Style Options:
    Caterpillar
    Position:
    Kit Full
    Product Type:
    Engine Parts
    Make:
    Universal Items
    $91.99
    Qty in Cart: 0
    Price:
    $91.99
    Subtotal:
  • 32 Inch Nylon 9 Blade Fan Blade Replaces 393256-32, 3415031, 3507212C1, 3571552C1, 981813253, 991813253

    32 Inch Nylon 9 Blade Fan Blade Replaces 393256-32, 3415031, 3507212C1, 3571552C1, 981813253, 991813253

    AUTOMANN USA

    $197.99
    32 Inch Fan Blade- 9 BladesKeep your truck engine cool under the toughest conditions with this high-quality 32 Inch Nylon 9 Blade Fan Blade. Featuring 9 blades made of durable nylon, clockwise...
    29-0706015
    SKU:
    29-0706015
    Material Options:
    Nylon
    Diameter Options:
    32 Inch
    Product Type:
    Engine Parts
    Make:
    Universal Items
    $197.99
    Qty in Cart: 0
    Price:
    $197.99
    Subtotal:
  • Thermostat Replaces 2477133, 7C3095, 34289 For Caterpillar

    Thermostat Replaces 2477133, 7C3095, 34289 For Caterpillar

    AUTOMANN USA

    $37.10
    1.811 X 2.26 Inch ThermostatPrevent engine overheating with this heavy-duty Caterpillar thermostat. Rated at 192F, it maintains proper engine temperature for maximum performance and reliability. With...
    29-07020004
    SKU:
    29-07020004
    Style Options:
    Caterpillar
    Product Type:
    Engine Parts
    Make:
    Universal Items
    $37.10
    Qty in Cart: 0
    Price:
    $37.10
    Subtotal:
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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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