Ok, so heres a break down from what ive learned the hard way..
you have 4 holes that need to breathe..
Your PCVs -
they are on the front side of the valve covers.
They dump 90% of the crap coming out of the crank case.
the hose inner diameter is 3/8" (metric equiv)
for forced induction, its highly recommended that to go to a catch can system with proper filtering here. its also recommended to drill out the pcv or get a pcv valve flow through from cjm. might want to plumb the exit from the catch can back to the intake pipes for proper vacuum..
if you do run the cjm flow through, that's 8an, so might want to run 1/2" elbow and hose to the catch can to reduce the amount of fittings and widen up the hose for more flow
I read on the gtr forums, that vacuum is an issue and that vent to atmosphere is counter-productive - in other words, anything that helps outflow the crankcase pressure under high boost is most likely best the best option.
your CCVs -
those are the holes to the back of the valve covers
drivers side is elbowed and the passenger side is straight
they hardly dump anything nasty if at all.
the hose inner diameter is 5/8
I dont see why these cannot be vented to air since they are fairly clean in comparison. running a line elbowed at the fender liner gap and down, secured and filtered should solve it.
IMO, i wouldnt add filters right at the pcv or ccv outlets.. these out outlets are pumping out noxious gases and they WILL get sucked up by your a/c - heater cabin inlet. Believe me i know... turning on the heater was short lived, i thought i was going to die of asphyxia. Not noticeable at highway speeds, but definitely at slower speeds. AND - the pcv will puke out sht and dirty up the engine
Disclaimer: do this at your own risk, drive the speed limit and drink plenty of water.