It is for the 7.3L engine and 6.0L has similar parts but an additional valve bridge worked by the rocker arm. First, eliminate the valve covers. Identify the rocker arms to be reinstalled and remove the rocker arm bolts in all the cylinder heads and then remove the rocker arms. Likewise mark the pushrods and remove them and make sure that each pushrod and rocker arm stays together in order that they may not be interchanged. When on the workbench remove the snap retainerring from the rocker arm followed by removal of the rocker arm pedestal and the rocker arm. Extract the steel ball from each of the above rocker arms, make sure not to misplace the ball and stack the dismantled components. For each rocker arm, examine it for signs of wear, and cracks, and damage at the friction surfaces, and replace these rocker arms. Inspect the steel balls for galling, scoring, and excessive wear and replace those balls which are bad. The pushrods are to be checked for cracks and for signs of wear and each pushrod must be rolled on a piece of plate glass to check for bending and the pushrod is to be replaced if it is damaged. Put the steel ball into the rocker arm cup and apply clean engine oil on to the ball, install the pedestal of the rocker arm on to the rocker arm and the steel ball. Slide the retaining clip over the rocker arm pedestal groove for 6.4L engines use new one during assembly of the engine. Grease the ends of the push rods with engine oil and then fit the push rods with the copper facing upwards, subsequently fit the rocker arms and the bolts properly and in the right order then tighten the bolts to the required torque. The only detail that can interfere with its correct installation is that during its assembly the valves may become bent; to avoid this, during the final moments of rotation of the engine, the bottoms of the pushrods of each cylinder must align and then the valve covers can be installed.