D&J Stage 1 Performance Head 03-07 Ram 5.9L Cummins

D&J Precision Machine is the name serious diesel enthusiasts trust for premium engine components engineered to handle extreme power, boost, and stress. From street-driven trucks to record-setting race builds, D&J provides the parts and expertise to push diesel performance to its absolute limits. Founded on a commitment to excellence and innovation, D&J has established itself as a leader in the high-performance diesel engine world. Whether you're building a reliable workhorse or a full competition drag or sled pull setup, D&J components are precision-built to deliver maximum power and unmatched durability. Known for race-winning cylinder heads, intake manifolds, short blocks, long blocks, and complete custom engines, D&J brings cutting-edge engineering and craftsmanship to every component. Every product is developed, machined, and assembled in the USA at D&J’s advanced facility. With in-house CNC machining, rigorous quality control, and a team of diesel performance experts, D&J ensures every component meets the strictest standards for performance and longevity. Whether it’s a forged long block built to handle over 2,000 horsepower or a flow-optimized head for better airflow and cooling, D&J’s diesel solutions are crafted with precision and built to win. D&J PRECISION MACHINE: DIESEL PERFORMANCE WITHOUT COMPROMISE D&J Precision Machine isn’t just about horsepower, it’s about building confidence. Builders and racers around the world rely on D&J because they know each product is designed for real-world abuse and engineered to last.When it’s time to go beyond stock and into elite performance territory, D&J Precision Machine delivers the diesel power, strength, and reliability you need to dominate the street, trail, or track. FREQUENTLY ASKED QUESTIONS We get a lot of calls and e-mails each day with various product, vehicle, and installation questions. Some are completely off the wall and can even catch us off guard at times, but many others are fairly routine, so we thought we'd post some of the most popular questions regarding D&J Precision Machine that can hopefully be a good resource for you. Q: What makes D&J Precision Machine products superior to OEM components? A: D&J Precision Machine components are built for unmatched strength, precision, and performance. These parts exceed OEM standards by utilizing advanced engineering and premium-grade materials, offering superior durability and power output for high-performance and racing applications. Q: What types of products does D&J Precision Machine manufacture? A: D&J offers a comprehensive lineup of performance diesel engine components, including billet cylinder heads, intake manifolds, short blocks, long blocks, race engines, and valvetrain upgrades. Their products are designed for everything from daily-driven trucks to full-blown competition builds. Q: Are D&J Precision Machine products suitable for performance applications? A: Absolutely. D&J is known for building race-winning engines and components that handle extreme horsepower, high boost levels, and demanding conditions. Their products are trusted by top-tier racers and serious diesel enthusiasts alike. Q: Are D&J Precision Machine parts compatible with any diesel engine? A: D&J specializes in high-performance diesel platforms, particularly Cummins engines, offering solutions for 5.9L, 6.7L, and competition-only variants. Each product is engineered for a precise fit and optimal integration with performance builds. Q: Why is upgrading to D&J Precision Machine components beneficial? A: Upgrading improves engine reliability, airflow, and power potential. These components are crafted for high-stress environments and are ideal for builds where OEM parts would fail under heavy loads or prolonged abuse. The result is a more capable and longer-lasting performance engine. Q: Where are D&J Precision Machine products made? A: All products are proudly designed and manufactured in the USA, with a focus on precision machining, top-tier materials, and rigorous quality control to ensure race-ready results. Q: Can D&J Precision Machine components be installed without professional help? A: While some components may be installed by experienced enthusiasts, most products, especially complete engines and head assemblies are best installed by professionals to guarantee proper setup, fitment, and performance. Q: Do D&J Precision Machine parts come with a warranty? A: Yes, warranty coverage is available and varies by product type. Specific warranty terms are provided with each item and should be reviewed before installation. Q: What is the history of D&J Precision Machine? A: Founded by passionate diesel performance specialists, D&J Precision Machine has built a reputation for engineering excellence and racing dominance. With years of engine-building experience and a commitment to innovation, D&J remains a trusted leader in the world of high-performance diesel.