Wehrli Valve Cover Billet WCFab X D J Precision 03-05 Cummins WCFab Grey WCFab Grey 100330-GRY

If you're looking to clean up your engine bay and add a serious dose of style and function to your 2003–2005 5.9L Cummins, the Wehrli Precision Billet Valve Cover is a top-tier upgrade that brings more than just good looks to the table. This isn’t some off-the-shelf dress-up piece—it’s a purpose-built, performance-driven component designed in collaboration with D&J Precision Machine and built to the high standards WCFab is known for. The cover is CNC-machined from aircraft-grade 6061-T6 aluminum, giving it exceptional strength and a clean, high-end finish that’s ready for any build, whether you're going for show quality or under-the-hood durability. Unlike stock stamped steel covers, this billet unit holds up to heat, vibration, and time without warping, leaking, or looking tired after a few years. And to make sure it looks as good as it performs, it comes powder coated in your choice of color—a perfect way to match the rest of your engine bay or make the valve cover the centerpiece.

Beyond aesthetics, this cover includes a fully integrated baffled breather system, designed to control crankcase pressure and reduce the chance of oil blow-by. It’s not just about keeping things cleaner—it’s about improving the overall breathing of your engine, especially important for high-performance applications or trucks that see long hours of heavy work. The package also includes D&J’s custom billet breather, a WCFab engraved billet cap, all stainless steel fasteners, and a 3/4\" hose, so you’re getting everything you need for a clean, leak-free install. It’s important to note that this cover is not compatible with WCFab’s billet aluminum oil fill caps (part numbers WCF100394 and WCF100395), so if you’re running those, you’ll want to plan accordingly. That said, the included components are purpose-built to work together and provide a bolt-on solution that fits flawlessly and functions exactly as intended.