CP3 Conversion High Pressure Line Upgrade Kit

Features:

• Fits 2011-2016 LML Duramax
• Designed for CP3 conversion setups
• Larger I D high pressure line
• Increased fuel volume capacity
• Longer line than street kits
• Larger I D rail fitting
• Improved high pressure fuel flow
• Supports 10mm 12mm 14mm CP3 pumps
• Ideal for high horsepower builds
• Optimized for performance applications
• Reduces restriction at fuel rail
• Built for demanding fuel systems

Feed Your LML The Fuel It Truly Demands

Once you step into a CP3 conversion on your 2011-2016 Silverado or Sierra 2500HD or 3500HD LML, fuel delivery becomes the name of the game. The Wehrli 100402 High Pressure Line Upgrade Kit is built for owners who are not interested in leaving power on the table. With a longer and larger inside diameter high pressure line than many standard street kits, this setup is designed to move more fuel where it needs to go. That added volume makes a real difference when you are leaning on a 10mm, 12mm, or 14mm CP3 pump and pushing for serious horsepower. Additionally, the larger inside diameter fitting at the rail helps reduce restriction right at the connection point, supporting smoother and more consistent fuel flow. Instead of wondering if your fuel system is becoming the bottleneck, you can focus on tuning and driving. For performance builds that demand more from the LML platform, this upgrade helps support the next level.

Engineered High Flow Solution For CP3 Converted LML Platforms

This kit was specifically developed for 2011-2016 LML Duramax trucks running a CP3 conversion, where fuel demand often exceeds what standard lines can efficiently support. The longer high pressure line with increased inside diameter allows for greater fuel volume compared to typical street series kits and many other conversion packages on the market. Furthermore, the upgraded high pressure rail fitting features a larger inside diameter than the factory style location, helping to minimize restriction at a critical junction. When paired with 10mm, 12mm, or 14mm CP3 pumps, this design supports improved flow characteristics under high load and high RPM conditions. Increased fuel delivery capacity is especially important in high horsepower or competition focused applications where consistent rail pressure matters. The result is a more capable high pressure fuel path that complements upgraded pumps and aggressive tuning. When installed correctly as part of a complete CP3 conversion, this line upgrade helps optimize the overall efficiency of your LML fuel system.

Fitment: 2011, 2012, 2013, 2014, 2015, 2016 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax LML

Notes:

• Fits 2011-2016 LML Duramax only
• For CP3 conversion applications only
• Not for factory CP4 systems
• Recommended for 10mm 12mm 14mm CP3
• Designed for high horsepower builds
• Requires proper CP3 conversion kit
• Professional installation strongly recommended
• Verify rail fitting compatibility
• Intended for performance fuel systems
• Tuning adjustments may be required
• Inspect fuel system before installation
• Ensure all connections properly torqued