I've seen this before, the oil is splashing, seeping, leaking out of the valley pan on the bottom side of the pan and heads, it is not sealing properly.
I would try thicker gaskets to seal it better.
If that doesn't work you may need to have the intake surfaces corrected to match the angle of the heads.
I've seen many aluminum intakes needing that
I found that out fighting the same thing but mine was sucking the oil into the intake ports, I remove the pan and cleaned up the heads and intake mating surfaces and set the intake on the heads and used feeler gauges to see how much gap was on all four corners at the top and bottom, it was easily measurable so I wrote them down and took it to a good machine shop and they fixed it by surfacing the intake