Product Description
Wehrli WCF100024 Valley CP3 Block Off Plate – 2001–2016 GM 6.6L Duramax
The WEHRLI WCF100024 Valley CP3 Block Off Plate is a simple but critical piece for any 2001–2016 GM 6.6L Duramax fuel system build. When you remove the factory CP3 pump from the engine valley for a dual-fueler setup, CP3 relocation, or full CP3 delete/CP3 conversion, this billet plate securely seals the original pump location to keep your engine bay clean and leak free.
CNC-machined from high-quality billet aluminum and finished in a durable black anodizing with an engraved WCFab logo, this block off plate looks as good as it performs. A quality O-ring is included to ensure a tight, leak-free seal at the valley opening, helping maintain rail pressure integrity and prevent unwanted fuel or oil seepage.
Key Features
- Billet aluminum construction for precise fit and long-term durability.
- Black anodized finish for corrosion resistance and a clean, professional look.
- Engraved Wehrli logo matches the rest of your WCFab hardware and under-hood upgrades.
- Includes O-ring to properly seal the factory valley CP3 pump opening.
- Ideal for dual-fueler & CP3 delete/conversion builds where the stock valley pump is removed.
- Direct-fit for 2001–2016 GM 6.6L Duramax (LB7, LLY, LBZ, LMM, LML).
Fitment
- 2001–2016 Chevrolet Silverado 2500HD / 3500HD 6.6L Duramax
- 2001–2016 GMC Sierra 2500HD / 3500HD 6.6L Duramax
- Engine codes:
- 2001–2004 LB7 Duramax
- 2004.5–2005 LLY Duramax
- 2006–2007 LBZ Duramax
- 2007.5–2010 LMM Duramax
- 2011–2016 LML Duramax
- Designed to seal the factory valley CP3 pump location when the OE pump has been removed.
When to Use This Block Off Plate
- Installing a dual fueler kit and relocating or deleting the factory valley CP3.
- Performing a CP3 conversion on LML trucks and removing the original pump location in the valley.
- Building a competition or high-output fuel system where the stock valley pump is no longer used.
- Any time the OEM valley CP3 is removed and the opening needs to be securely sealed.
What’s Included
- (1) Wehrli WCF100024 billet valley CP3 block off plate
- (1) O-ring for block off plate sealing surface
Benefits
- Prevents leaks at the valley CP3 location after the pump is removed.
- Keeps the engine bay clean by sealing off an otherwise open fuel system cavity.
- Supports reliable high-pressure fuel operation in dual-fueler and conversion setups.
- Matches other WCFab components with its black anodized, engraved finish.
Recommended Wehrli Upgrades & Related Parts
- For LB7 fuel system clean-up and Y-bridge clearance:
WEHRLI WCF100023 Fuel Pressure Relief Valve Delete Kit – 01–04 GM 6.6L LB7 Duramax - For turbo resonator block off on LML trucks:
WEHRLI WCF100096 Turbo Resonator Billet Block Off Plate – 11–16 Chevrolet 6.6L LML Duramax - For LML CP3 conversion fuel line routing:
WEHRLI WCF100402 6.6L LML Duramax High Pressure Line CP3 Conversion Kit - For LB7 airflow upgrades that pair well with fuel system mods:
WEHRLI WCF100342 3.5in Intake Horn – 01–04 Chevrolet 6.6L LB7 Duramax
WEHRLI WCF100119 3in Down Pipe – 01–04 Chevrolet 6.6L LB7 Duramax
Installation Notes
- Verify the valley CP3 pump has been fully removed and the sealing surface is clean and free of debris.
- Lightly lubricate the supplied O-ring before installation.
- Torque the block off plate evenly in a crisscross pattern according to typical aluminum cover fastener specs.
- Cycle the key and inspect for leaks before starting the engine under load.
Emissions & Usage Notice
This product is intended for off-road competition use and race vehicles in emissions-controlled regions. It may not be legal for street-driven vehicles in some areas. Always check and comply with your local, state, and federal emissions regulations before installation.
FAQ
Do I need this plate for a dual fueler or CP3 relocation kit?
Yes. Any time you remove the factory CP3 pump from the engine valley, you must seal the original pump opening. The WCF100024 block off plate is designed specifically to close off that location on 2001–2016 Duramax engines.
Will this fit all 2001–2016 Duramax engine codes?
The WCF100024 plate is designed for all 6.6L Duramax platforms from 2001–2016, including LB7, LLY, LBZ, LMM, and LML. As long as you are sealing the OEM valley CP3 pump location on a 6.6L Duramax, this plate will fit.
Is any tuning required after installing this block off plate?
The block off plate itself does not require tuning. However, the fuel system changes that go along with removing the factory CP3 (dual fueler, CP3 conversion, or delete) typically require appropriate tuning. Work with a reputable tuner for your specific setup.
Does the kit include mounting hardware?
The kit includes the billet block off plate and O-ring. In most builds, installers reuse suitable existing hardware or hardware supplied with their fuel system kit. Confirm your hardware before disassembly so you have everything needed on hand.
Is this part legal for on-road use?
Because this plate is commonly used in conjunction with significant fuel system modifications, it is generally intended for off-road, race, or competition vehicles. Always verify the laws in your area before modifying emissions-related components on a street-driven truck.
