Measure the rocker arm I.D. (Item 1) [Figure 70-80-37] with an inside micrometer.
Measure the rocker arm shaft O.D. (Item 2) [Figure 70-80-37] with an outside micrometer.
If the clearance exceeds the allowable limit, replace the bushing.
If the clearance still exceeds the allowable limit after the bushing is replace, replace the rocker arm shaft.