Stage 3 CNC-Ported Race Cylinder Head

The Power Driven Diesel Stage 3 CNC-Ported Race Cylinder Head is built for high-performance 1989-1998 12v Cummins engines. It starts with a new aftermarket casting that is precisely surfaced in-house to OEM specifications, then machined for fire-rings to provide the ultimate seal when used with a fire-ring head gasket. This head incorporates Power Driven's aggressive Race Port, enlarged pushrod holes for enhanced clearance and oil drain-back, and threaded freeze plugs for dependable operation at high RPMs. Following the CNC porting process, the valve seats are modified to accommodate larger aftermarket 1.87-inch intake and 1.75-inch exhaust valves. The head is also machined to be compatible with Power Driven's Doweled Batwing Rocker Pedestals. Expert technicians assemble each head with OEM top-hat-style seals and Power Driven Race Conical Valve Springs. The Power Driven Diesel Race Port is the most extreme CNC porting option available while maintaining the factory intake shelf and water cooling. It has been tested on a SuperFlow 1020 bench, achieving a 68% increase in intake flow and a 65% increase in exhaust flow, resulting in an impressive 234 CFM intake and 232 CFM exhaust flow at 28 inches of water. In dyno testing on a 1,500 hp race truck, this increased flow led to a 119 hp gain over a baseline stock head. This cylinder head is intended for use with an aftermarket high-lift camshaft and is not recommended for street use due to thin port walls and heavy valve spring pressure, which can impact longevity in a street application. It is ideal for dedicated 12v Cummins race engines requiring an ultimate water-cooled head. Compatibility includes: 1989-1998 Dodge 5.9L 12v Cummins engines. Please note that performance may vary based on other engine/vehicle modifications. This product cannot ship to California.