


Sinister Diesel Billet Valve Covers for 2004.5–2010 Duramax LLY/LBZ/LMM | Blue Anodized
Clean up your Duramax engine bay and gain additional clearance for custom turbo or fuel upgrades with Sinister Diesel Billet Valve Covers. Fully CNC-machined and anodized in Sinister Blue, these covers pair a refined under-hood look with a layout suited to modified builds.
They retain the factory fuel filter housing and radiator hose hard line, so you can plan your upgrades around those existing components.
Key features
- Fully CNC-machined billet construction.
- Sinister Blue anodized finish.
- Additional clearance for custom turbo or fuel upgrades.
- Retains the factory fuel filter housing and radiator hose hard line.
- Upper valve cover includes new gaskets.
- Works with factory hardware or compatible aftermarket hardware, including the ARP dress-up kit.
Vehicle fitment
2004.5–2010 Chevrolet/GMC 2500 and 3500 trucks with the 6.6L Duramax LLY, LBZ or LMM diesel engine. Confirm your model year and engine code before ordering.
Important installation notes
These covers do not include additional mounting provisions for wiring harnesses or accessories. Installation on a stock truck requires the wiring harness to be tied back.
Build-to-order lead time
This item is built to order with an approximate 60-day build time. Plan your installation accordingly and confirm availability if timing is critical.

