compedgemarine

looks like the ZZ502 w/aluminum heads uses stamped adjustable rockers. any one know if they are the same rockers as a MK4 454 etc? my dads boat has stock ZZ502's and one has a noise in the upper end and seems down on a cylinder some and not sure if it is a valve spring or rocker maybe but want to gather some parts before I drive the 3 hours back to work on it.