Elevate your late 5.9 Cummins or 6.7 Cummins engine build with the G&R Diesel Billet Rocker Box — a premium, precision-engineered upgrade designed for enthusiasts and professionals who demand uncompromising quality, strength, and reliability in high-performance diesel applications. Premium Construction & Materials CNC-machined from high-grade 6061-T6 aluminum, this rocker box delivers exceptional strength-to-weight ratio while maintaining the structural integrity required for demanding street, towing, and competition environments. Integrated steel threaded bosses are precision-installed to completely eliminate the risk of thread stripping — a common failure point in high-vibration, high-boost, or frequently serviced engines. Every unit is proudly manufactured in the USA to exacting standards. Key Features & Design Advantages Head Stud Clearance: The rear of the rocker box is strategically machined to provide generous clearance for aftermarket head studs, ensuring seamless compatibility with upgraded head gasket and fastener setups without requiring modifications. Robust Billet Construction: Full billet aluminum body with a clean, professional finish that enhances the under-hood appearance of any late 5.9 or 6.7 Cummins engine bay. Enhanced Durability: Designed to withstand the rigors of elevated cylinder pressures, increased valve train loads, and sustained high-RPM operation typical of performance Cummins builds. Precision Fitment: Engineered specifically for 2006 and newer Cummins 5.9 and 6.7 engines, offering a direct bolt-on solution that maintains factory geometry while significantly upgrading strength and aesthetics. Why Choose the G&R Diesel Billet Rocker Box? This component is more than a cosmetic upgrade — it addresses real-world weaknesses in the factory rocker box design while adding a distinctive, high-end look that signals a thoughtfully built engine. Whether you're chasing maximum reliability for daily driving and heavy towing or pushing the limits in competitive settings, the combination of aircraft-grade aluminum, reinforced steel inserts, and thoughtful machining delivers confidence-inspiring performance you can trust for years to come. Perfect for any serious late 5.9 or 6.7 Cummins build focused on longevity, power output, and standout engine bay presentation. Pair it with other G&R Diesel components for a cohesive, top-tier valvetrain and appearance package. Part # GRD67CM3015 Compatible with: Cummins, Engine & Engine Parts
