Hi JV
Yes you are right "A" is the spot for a catch can or Air Oil Separator. See my posting about using an AOS to stop the gunk going back into the engine.
By using an AOS or catch can we can can have our Cake without the nasty Frosting!
Just think what the "Frosting" is doing inside our engines--and remember it was
always going in thru PCV and Breather hose.
I'm still toying w/ a homemade catch can setup, have a small technical issue to solve. If I solve that, I have a design with an important (IMHO) feature I don't see so far on ANY catch can I see for sale anywhere. We will see how this one goes...
Thanks for your posting and diagram on this issue this will help many others trying to understand this!
TracyG Gadgetman Reno