To remove the valve covers begin with easing the rocker arm shaft retaining bolt in stages, at least two or three times with a small interval in order not to bend the shaft and starting from the outermost bolts. Some of the valves will still be open and the rocker arm shafts will be under spring tension, therefore do not undo any bolt entirely near a rocker arm under tension. Before you remove them you want to label each of the rockers for the specific part of the engine they were located at, so for instance if it was an FI rocker it would be marked Fl for Front Intake and if it was FE it then would be marked Front Exhaust. Unbolt and take off the rocker arm shaft assemblies one at a time and put them on a work bench in the order they were removed, make sure the shaft's with bigger notches are on the
Intake Manifold side. To inspect, observe the Conditions of the rocker arms and shafts and get the measurement of the outside diameter of rocker arm shaft at each journal with the revised diameter. Check each rocker arm bore to the shaft and record the ID of each rocker arm; calculate the clearance by subtracting the shaft diameter from the bore diameter, and the clearance should be within the specified figures. When the values in the said equations are beyond the limit, the rocker arms and shafts have to be replaced. To install, reverse the removal process and tighten the rocker arm shaft retaining bolt serially in equal turns starting from the two adjacent bolt ends.