when going to add -an fittings onto a valve cover, do you drill a hole through the baffeling as well or just through the primairy metal infront of the baffeling?

 

Either. If you tap into the area that is not baffled then you will gather more oil in your catch can.

 

just drill through the outter wall of the front of the valve cover, it will vent just fine doing it like that. some will add another two vents to the back of the valve cover and will weld some baffling pieces to limit the oil venting into the catch can