From many years of laps:

Use a pcv oil separator - the mustang aftermarket one works wonderful. Let the whining begin about it's a ford part.

The valve covers need to breath-I ran a catch tank [with a breather filter on top] to the stock breather cap for the valve covers. On tight motors this will suffice. On project blacknblue the 440 was loose so the oil filler was used as the second breather outlet. It worked well only venting one side. The dip stick tube should also have a hose running to a small breather tank. I never had to run a race type set up to vent the valve covers, then again the motors were never spun over 6000 rpm.