Product Description
Feed big injectors and high boost the right way. The INDUSTRIAL INJECTION 433402 Dual CP3 “kit only” adds a second high-pressure pump to your 2004.5–2005 6.6L Duramax LLY using proven brackets, lines, and an electronic controller. By splitting the workload between two pumps, the system maintains commanded rail pressure under load, reduces drive stress on the factory pump, and provides failover control if one pump goes down—ideal for serious street/strip and competition builds.
Fitment
- 2004.5–2005 GM 6.6L Duramax LLY (Silverado/Sierra HD)
- Does NOT fit early-2004 LB7 trucks.
What’s Included (Kit Only, No Pump)
- Upper pump mounting brackets & hardware
- High-pressure/return line plumbing and fittings
- Belt-drive components and pulley hardware
- Dual-CP3 electronic controller with automatic single-pump failover
- Install instructions
Why Dual CP3?
- Stable rail pressure at high fuel demand—cleaner, safer power under load
- Shares the load—each pump supplies roughly half the volume, improving reliability
- Controller failover—continues operation on a single pump in the event of failure
Recommended Parts (CPP Internal Links)
- GM DURAMAX CP3 PUMPS & COMPONENTS — choose your primary/secondary pump (LBZ-based CP3s recommended)
- S&S CP3-DMX-10-HS (10mm) — 01–10 LB7/LLY/LBZ
- S&S CP3-DMX-12-HS (12mm) — 01–10 LB7/LLY/LBZ
- S&S CP3-DMX-14 (14mm) — 01–10 LB7/LLY/LBZ
- S&S Reverse-Rotation CP3 (for secondary/front pump when required by kit)
- GM DURAMAX LIFT PUMPS — stabilize CP3 supply and protect the system
- S&S 45% Over (NEW) Injectors — 04.5–05 LLY or 400% Over (Reman) — Competition
Helpful Notes
- This is the kit only. Order your CP3 pump(s) separately.
- Professional installation and custom tuning are recommended for high-flow injector setups.
- Verify whether your upper/secondary pump position requires a reverse-rotation CP3.
- Add a quality lift pump to maintain inlet supply and extend CP3 life.
FAQ
Do I need tuning after installing a dual CP3 kit?Moderate builds may operate on stock calibration, but higher-flow injectors/turbos typically require custom tuning to command and control additional rail pressure and fueling.
Will this fit my early-2004 Duramax?No. This kit is designed for mid-year 2004.5–2005 LLY trucks, not early-2004 LB7 models.
What happens if one pump fails?The included controller provides an automatic failover strategy that lets the remaining pump maintain operation so you can safely get off the road or finish a pass.
Is a lift pump required?Strongly recommended. A lift pump stabilizes supply pressure to the CP3(s), improves longevity, and helps prevent pressure drop at WOT.
