Ant:
I am no expert, hence my original post. But from what has been said on this thread I am doing two things:
1. Added a PCV valve to my Cobra's 427 side oiler on one side, vented filler cover on the other. Easy to do with a Holley carb.
2. Adding a recovery tank connected to vents on both valve covers on my 302 with Webers, since there is no easy vacuum source for a PCV. Moroso and Canton make nice spun aluminum ones.
Can't say which is right or which is better, but it would seem that both work, and both are better than just a breather cap without a recovery tank or PCV valve. Guess I will have both options covered, albeit on different cars!