The 1989-2015 Cummins 24 valve head on the 5.9 and 6.7 comes equipped with a press in casting plug, sometimes referred to as a freeze plug. These plugs are fairly thin in construction, and do not stand up well to corrosion. Another problem with these plugs is that pressure within the coolant system can actually blow these out, filling the engine with coolant. We all know how poor of a lubricant coolant is, and how costly the repairs can become. Think of this kit as a bit of insurance, after all an ounce of prevention is worth a pound of cure.
Our billet aluminum design not only looks good but functions much better than the oem design. You will need to remove the valve cover and most likely the rocker arms, clean all the oil from that side of the head and remove the casting (freeze) plugs. That allows for an easier install.