If you own a modern diesel truck, you know the factory CP4 fuel pump can be a ticking time bomb. A catastrophic failure can send metal shrapnel through your entire fuel system, leaving you with a massive repair bill. That’s why many owners turn to CP3 conversion kits, which swap the fragile CP4 for the legendary Bosch CP3 pump, known for its durability and reliability.
This guide reviews the best CP3 conversion kits on the market, covering options for both Duramax and Cummins engines. Whether you’re looking for a complete kit with a pump or just the hardware, you’ll find the information you need to make an informed choice and protect your investment.
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Cp3 Conversion Kit With Cp3 For 2011-2016 Lml Duramax
Best forReliable LML replacement
- Quality materials
- Perfect fit
ConsiderPrice may be high
BD Diesel Venom CP3 Conversion Kit for Chevy/GMC Duramax 2011-2016 with Sta…
Best forPerformance-oriented Duramax
- Complete kit
- High-performance pump
ConsiderPremium price
Fleece Performance – 11-16 GM 2500/3500 Duramax LML CP3 Conversion Kit w/HD…
Best forHeavy-duty towing use
- HD pump included
- Durable construction
ConsiderHigher cost
BIGREAT CP4 to CP3 Fuel Injection Pump Upgrade Conversion Kit
Best forBudget-conscious Duramax owners
- Affordable price
- Corrosion-resistant
ConsiderBrand less known
S&S Diesel Motorsport® RAM CP3 Conversion Kit With 50 State Pump Compatible…
Best for2019-2020 Cummins trucks
- No tuning needed
- Bosch CP3NH pump
ConsiderLimited to specific years
AUTOVIC CP3 Conversion Kit for 2011-2016 LML 6.6L Duramax Diesel
Best forDIY installation projects
- Complete hardware
- High-flow fittings
ConsiderPump not included
Industrial Injection LML Duramax CP4 to CP3 Conversion Kit with Pump, Emiss…
Best forEmissions-compliant upgrades
- Tuning-free
- Emissions compliant
ConsiderMay be pricey
Industrial Injection 436403 Conversion Kit With Pump (Tuning Reqd, 11-15 Gm…
Best forTuned performance builds
- US-made
- Includes pump
ConsiderRequires tuning
Fleece Performance Engineering -LML-CP3-FF-10 2011-2013 Lml Cp3 Conversion …
Best forHigh-horsepower applications
- PowerFlo 750 pump
- High flow
ConsiderLimited to 2011-2013
Fleece Performance – 11-16 GM 2500/3500 Duramax LML CP3 Conversion Hardware…
Best forCustom pump selection
- Flexible pump choice
- Quality materials
ConsiderPump not included
Fleece Performance CP3 Kit – Reliable Upgrade
Brand: Fleece Performance Engineering
A dependable hardware kit for LML owners seeking reliability.
The Fleece Performance CP3 Conversion Kit is a solid choice for 2011-2016 LML Duramax owners. It includes replacement parts made from quality materials, designed to fit your vehicle perfectly. This kit is part of Fleece’s injection pumps and controllers lineup, ensuring you get a product backed by a reputable brand.
You’ll appreciate the straightforward installation and the peace of mind that comes with replacing your CP4. The kit is engineered to work seamlessly with your truck, providing reliable fuel delivery. If you want a dependable conversion without extra frills, this is a great option.
- Quality materials
- Perfect fit
- Trusted brand
- Price may be high
- No pump included
BD Diesel Venom CP3 Kit – Performance Choice
Brand: East Coast Diesel
A high-quality conversion for Duramax owners seeking performance.
The BD Diesel Venom CP3 Conversion Kit, available from East Coast Diesel, is designed for 2011-2016 Chevy/GMC Duramax trucks. This kit includes the standard Venom CP3 pump, known for its performance and durability. It’s a complete solution to replace the problematic CP4.
You’ll benefit from BD Diesel’s reputation for quality and performance. The kit is engineered to deliver reliable fuel pressure and flow, which can support higher horsepower applications. If you’re looking to upgrade your truck’s fuel system with a proven name, this kit is worth considering.
- Complete kit
- High-performance pump
- Easy install
- Premium price
- May require tuning
Fleece HD CP3 Kit – Heavy-Duty Solution
Brand: Fleece Performance Engineering
A sturdy kit for those who demand maximum reliability.
This Fleece Performance kit is tailored for 2011-2016 GM 2500/3500 Duramax LML trucks, featuring the HD CP3 pump. It’s built with replacement parts from quality materials, designed to fit your vehicle precisely. The kit is part of Fleece’s injection pumps and controllers line, ensuring reliability.
You’ll get a robust conversion that can handle demanding conditions. The HD CP3 pump is known for its durability and ability to support higher fuel volumes. If you use your truck for heavy towing or performance, this kit provides the reliability you need.
- HD pump included
- Durable construction
- Vehicle-specific fit
- Higher cost
- Installation complexity
BIGREAT CP3 Upgrade – Budget-Friendly Option
The BIGREAT CP4 to CP3 Conversion Kit is compatible with 2011-2016 Chevy Silverado and GMC Sierra 2500/3500 HD with the 6.6L Duramax. It allows you to upgrade to the far more reliable CP3, eliminating the factory CP4 pump. The kit is made from high-quality materials, offering excellent corrosion and oxidation resistance.
You’ll find this kit improves your LML Duramax’s reliability and fueling capability. It’s a cost-effective solution compared to other brands, making it accessible for many owners. If you’re on a budget but want to protect your engine, this is a smart pick.
- Affordable price
- Corrosion-resistant
- Improves reliability
- Brand less known
- No pump included
S&S Diesel RAM CP3 Kit – Cummins Solution
The S&S Diesel Motorsport RAM CP3 Conversion Kit is designed for 2019-2020 Dodge Ram 6.7L Cummins. It features a brand-new Bosch CP3NH base pump that is internally modified for improved durability. This kit requires no tuning, making installation straightforward.
You’ll benefit from S&S’s extensive experience in fuel systems, ensuring a refined solution. The kit addresses the known issues with the CP4 in newer Cummins engines, providing peace of mind. If you own a late-model Ram, this is a top-tier conversion option.
- No tuning needed
- Bosch CP3NH pump
- Proven design
- Limited to specific years
- Premium price
AUTOVIC CP3 Hardware Kit – DIY Friendly
The AUTOVIC CP3 Conversion Kit is tailored for 2011-2016 Chevy Silverado and GMC Sierra with the 6.6L LML Duramax. This complete hardware kit includes the CP3 mounting adapter, high-pressure line, fuel fittings, and all necessary hardware, but the CP3 pump is not included. It’s designed to mitigate potential CP4 issues.
You’ll appreciate the high-flow CP3 feed and return fittings that maximize fuel volume, ensuring efficient delivery for stock or modified setups. This kit is ideal for DIYers who already have a CP3 pump or plan to purchase one separately. It’s a practical and cost-effective solution.
- Complete hardware
- High-flow fittings
- No pump needed
- Pump not included
- Requires mechanical skill
Industrial Injection Tuning-Free Kit – Easy Install
Brand: Industrial Injection
A hassle-free conversion that keeps your truck compliant.
The Industrial Injection LML Duramax CP4 to CP3 Conversion Kit includes the pump and is emissions intact. It offers tuning-free installation, meaning no modifications are required. The kit has a proven track record for reliable performance and meets emissions regulations.
You’ll get peace of mind with worry-free operation, knowing your fuel system is protected. Industrial Injection is a trusted name in diesel performance, and this kit reflects their quality. If you want a straightforward conversion that keeps your truck legal, this is an excellent choice.
- Tuning-free
- Emissions compliant
- Proven reliability
- May be pricey
- Limited availability
Industrial Injection Tuning Required Kit – Performance
Brand: Industrial Injection
A performance-focused kit for those planning to tune.
The Industrial Injection 436403 Conversion Kit is for 2011-2015 GM Duramax 6.6L LML, and it requires tuning. This kit includes the pump and is manufactured in the United States. Industrial Injection designs and delivers top-quality products using advanced technology.
You’ll get a performance-oriented conversion that can support higher horsepower with proper tuning. The kit is built with a strong desire to lead diesel innovation, ensuring you receive a reliable product. If you’re planning to tune your truck, this kit is a solid foundation.
- US-made
- Includes pump
- Advanced design
- Requires tuning
- Not for stock trucks
Fleece PowerFlo 750 Kit – High Flow
Brand: Fleece Performance Engineering
A top-tier choice for serious performance enthusiasts.
The Fleece Performance Engineering LML-CP3-FF-10 kit is designed for 2011-2013 LML Duramax and includes the PowerFlo 750 CP3 pump. This kit is known for its high-flow capabilities, making it ideal for modified trucks. It comes as a complete package with all necessary components.
You’ll benefit from the PowerFlo 750’s ability to deliver substantial fuel volume, which is essential for performance applications. The kit is built to Fleece’s high standards, ensuring durability and reliability. If you’re pushing your truck’s limits, this kit won’t let you down.
- PowerFlo 750 pump
- High flow
- Complete package
- Limited to 2011-2013
- Premium price
Fleece Hardware Kit – Flexible Option
Brand: Fleece Performance Engineering
A versatile hardware kit for those who want to choose their pump.
The Fleece Performance 11-16 GM 2500/3500 Duramax LML CP3 Conversion Hardware Kit comes without a pump, giving you flexibility. It includes replacement parts made from quality materials, designed to fit your vehicle. This kit is part of Fleece’s injection pumps and controllers line.
You can pair this hardware with your choice of CP3 pump, whether stock or aftermarket. It’s a great option if you already have a pump or want to select a specific model. The kit ensures a precise fit and reliable performance, backed by Fleece’s reputation.
- Flexible pump choice
- Quality materials
- Precise fit
- Pump not included
- Installation required
Buyer’s Guide: What to Consider
Choosing the right CP3 conversion kit involves several key factors. This guide highlights what to consider to ensure you get a kit that fits your vehicle, meets your needs, and provides reliable performance.
- Compatibility: Ensure the kit matches your vehicle's make, model, and year. For Duramax, confirm it's for LML (2011-2016). For Cummins, check if it's for 2019-2020 or other years. Using the wrong kit can lead to installation issues.
- Pump Included: Some kits include a CP3 pump, while others are hardware-only. If you already have a pump or plan to buy one separately, a hardware kit saves money. Complete kits offer convenience and ensure compatibility.
- Tuning Requirements: Some conversions are tuning-free, meaning no ECU modifications are needed. Others require tuning to optimize performance and avoid codes. Consider your willingness to tune your truck before purchasing.
- Emissions Compliance: If your truck must pass emissions tests, choose a kit that is emissions-intact. Some kits remove or alter emissions components, which could cause legal issues. Look for explicit emissions compliance claims.
- Brand Reputation: Opt for kits from reputable brands like Fleece, Industrial Injection, or S&S Diesel. They have proven track records and quality control. Lesser-known brands may offer lower prices but could compromise reliability.
Conclusion
CP3 conversion kits are a smart investment for diesel truck owners looking to avoid CP4 failures. Whether you drive a Duramax or Cummins, there’s a kit that fits your needs and budget. From budget-friendly options to high-performance setups, the kits reviewed here offer reliable solutions.
For most owners, a complete kit with a pump from a trusted brand like Fleece or Industrial Injection is the best choice. If you’re on a budget, the BIGREAT kit is a solid entry point. Always ensure compatibility and consider tuning requirements before purchasing.
Erica Steven is the founder and lead writer of WorstBrands, a site dedicated to providing honest and trustworthy reviews about outdoor gear and fashion products.
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