Do you have and use a stock type PCV system? If not that may help you when cruising at part throttle
I ended up having to use two PCV valves with two large breather caps, one on each side of both valve covers my old 518 C.I. pump gas street motor to help stop the oil breather caps from dripping oil out of them. I would wash them out in cleaning solvent every two or three months to help keep them from getting oil soak
Let us know what you do, we don't call them elephant motors Hemi roids for nothing
They can be a true pain in the rear