Factory rockers?
I never use bolts there. Even with factory rockers, I will use studs so that you don't have a fastener trying to pull the threads out of the aluminum. All of your aftermarket rockers will come with studs also.
You should be able to use a helicoil to repair it, but it's not going to be easy as you will have to grind some of it away to clear the
oil feed hole, or get a short one so it doesn't stick up as high.
Patrick, it depends on which rocker system it is. Not all of them have necked down bolts/studs on the
oil feed.