Ok. I only ask, because it's not uncommon for the rocker box gaskets to leak, and sometimes, oil can "travel" due to wind, and look like its coming from one place, when it's really coming from another.
In this case, you need to make sure it's not oil venting from the air cleaner, and just landing on the rocker box......
“When the going gets weird, the weird turn professional....” ~ Hunter S. Thompson~
R.I.P. Rubberdown. 1971-2012