The Heavy Hauler 6.7 Cummins Long Block is designed for demanding work trucks, towing applications, and high-horsepower builds, delivering up to 700 HP while improving airflow, efficiency, and durability. Built with a D&J Stage 1 High-Performance Cylinder Head, a street/towing camshaft for lower EGTs, and custom ARP 9/16 head studs for superior sealing, this long block ensures maximum strength under extreme loads. To increase reliability, this build incorporates 2018 and older engine components, replacing hydraulic roller lifters with solid flat tappets and adjustable rockers. Each engine is CNC-machined, fully blueprinted, and assembled with premium components, ensuring maximum strength and longevity. Manufactured by D&J Precision Machine, this engine is built to outperform and outlast stock configurations in the toughest applications.