Product Description
Backdate your LML to proven CP3 reliability and add serious fueling headroom with the INDUSTRIAL INJECTION 436405 CP4-to-CP3 Conversion Kit. This package includes the 85% over 10mm Dragon Fire CP3 and conversion hardware engineered for high-power builds.
Fitment
- 2011–2016 Chevrolet Silverado / GMC Sierra 2500HD & 3500HD — 6.6L Duramax LML (VIN 8)
What’s Included
- Industrial Injection Dragon Fire 85% over (10mm) CP3 injection pump
- CP4-to-CP3 conversion hardware for LML installation
- Warranty: 1 year (see product page for details)
- Core charge may apply (see options at checkout)
Key Features
- Replaces failure-prone CP4 with robust CP3 architecture
- 85% over fueling capacity — capable of supporting 800+ HP with proper supporting mods
- Designed for competition/off-road builds where higher, more stable rail pressure is required
Recommended Parts (CPP Internal Links)
- Fleece PowerFlo In-Tank Lift Pump (Short Bed, 2011–2016 LML)
- Fleece PowerFlo In-Tank Lift Pump (Long Bed, 2011–2016 LML)
- AirDog II-5G DF-165 System (select LML years)
- Shop GM CP3 Pumps & Components
- Shop All GM Duramax Categories
Cross-Reference / Alternatives
- Industrial Injection 436404 — 42% Over SHO Pump
- Industrial Injection 436406 — 120% Over 12mm Dragon Fire Pump
- Industrial Injection 436401 — With Pump (No Tuning Required)
Helpful Notes
- Tuning required: Custom calibration is required for this 85% over kit. Verify with your tuner before installation.
- Fuel system health and proper filtration/lift pump are strongly recommended for reliability at elevated power levels.
- Competition/off-road use only. Buyer is responsible for compliance with all emissions regulations.
FAQ
Does this kit require tuning?Yes. The 85% over Dragon Fire pump requires custom tuning to command and control the additional fueling on the LML platform.
Is this emissions-compliant?No. This competition part is not legal for on-road use. It’s intended for closed-course/competition vehicles only.
What horsepower can this support?With the correct turbo, injectors, lift pump, and tuning, the 85% over pump can support 800+ HP. Actual results vary by setup.
Do I need a lift pump?Highly recommended. A quality in-tank or frame-mounted lift pump stabilizes supply pressure and helps protect the CP3 under heavy load.
Is there a core charge?Yes, a core charge may apply. See the product options during checkout for current core details.
