Are you building your 6.7L Cummins to handle more power? The D&J Precision Machine Stage 1 Performance Head is built to solve the common issues that plague stock heads: airflow limitations, heat management, and long-term durability, all while giving your engine the ability to perform under real diesel conditions.

This is a smart upgrade for daily drivers, tow rigs, and moderately built trucks that need more reliability and better efficiency without going overboard. You’ll see improved airflow, more efficient combustion, and a more stable engine under load, especially when towing or running tuning. It’s the kind of upgrade that not only restores performance but builds confidence in your setup, knowing your top end can handle what you throw at it.

Each Stage 1 head starts as a fully remanufactured casting that is completely disassembled, cleaned, inspected, and precision-machined to restore and improve critical tolerances. Advanced CNC machining and valve work help improve airflow characteristics while ensuring proper sealing and consistency across all cylinders.

This head builds on a proven foundation with performance-focused upgrades, including improved port design, upgraded valve springs, and reinforced valve seat areas to better handle increased boost and cylinder pressure. Many Stage 1 heads in this category are CNC-ported and designed to support higher airflow and greater durability than stock configurations.