Possible oiling concerns

Slant six motors with hydraulic lifters get oil to the hydraulic lifters through the push rods.
On both mechanical and hydraulic lifter slants even at idle there should be some oil leaking out around the rockers and shaft as well as some oil spraying from the rocker arm tip on to the top end of the valve - valve spring.
That oil then flows across the top of the cylinder head to the top of the lifter chamber and to the cam shaft. The cam shift lobes are also lubricated by the oil that gushes out if the cam bearings.

as mentioned previously, post a link to the video.