Replace the warped, cracked, or damaged Cylinder Heads and upgrade your 1994-1998 Dodge 5.9L Diesel. The most common failure of cylinder heads is due to overheating, which can be caused by coolant loss or restricted coolant flow and head gasket failure. When a cylinder head gets too hot it can warp or crack and require extensive machine work or replacement. When a head is heated past normal operating temperatures, it expands past its limits. As it cools, the head often will not return to its original size or shape, instead settling into a more bent or distorted form. In extreme cases of overheating, the cylinder head can crack and typically needs to be replaced. O-Rings or Fire Rings are the perfect option for mild to high performance builds. A fire ring cylinder head has a small groove machined into the cylinder head around each combustion chamber. A stainless-steel ring is then inserted into it. The ring creates an additional seal that contacts the outer edge of the fire ring in the head gasket. This helps provide a better seal around the combustion chamber. A cylinder head with a machined fire ring ensures greater reliability under extreme stress. This is a must-have for higher horsepower diesel engines. Find everything you need for your vehicle whether you are searching for factory OE-replacements or performance aftermarket cylinder heads. Both remanufactured heads and brand-new castings are available in either cast-iron or aluminum construction. Offered as bare heads or complete with the valvetrain installed. These fully loaded heads are ready to bolt-on right out of the box and include upgraded valves, seals, retainers, locks, valve springs, as well as hardened seats and guides. High-performance heads are designed to increase flow for more horsepower and torque. Other benefits can include improved cooling and even a weight reduction compared to the stock heads. Shop all the leading manufacturers including Fleece Performance, ProMaxx Performance, Industrial Injection, Edelbrock, Powerstroke Products, and more!