How does oil get to rockers with solid cam setup

The only thing I'll add is I've found it common that the holes that go from the cam to the block in the cam bearings are not perfectly aligned with the holes in the block. So I'll add some chamfer to the backsides of the cam bearing to allow as much oil as possible per rotation to get into the passage. You can also partially or fully grove the cam journal. However either of those should be accompanied by drilling the cam-to-main saddle passage larger to make sure the main and rod bearings don;t suffer.