I am putting an LS7 into a '68 Camaro, and I am not sure how to run the PCV lines mostly due to my aftermarket oil tank. The stock setup on the 'vette is very similar to the LS2. There is no PCV valve, and the intake sucks air out of the valley cover. Supply air for the opposite side of the system is drawn from the intake tube and then into the valve covers. However, unlike the LS2 the supply air is routed through the dry sump tank. There are in and out fittings on the top of the stock oil tank.
On my car, I have a Peterson 2 gal. tank that has one -12 AN breather fitting at the top of the tank. Due the scavenge pump pulling at least some air out of the pan, the tank has to breath somewhere. Obviously, it would be easiest to breath it to atmosphere. Since I am going to run a MAF, if I want to keep a PCV system, I can't do that. Also, I would like to run a catch can somewhere.
Here is what I was thinking: Catch can between the valley cover and the intake (the normal spot). Draw supply air from the intake tube in front of the TB. Put a tee on the fitting on the dry sump tank. Then route to each valve cover. This is basically the same as the stock setup. I am concerned that the tee fitting might not breath the tank properly. The problem I can foresee is that it might push oil into the intake tube at WOT. The last thing I want is to get oil into the intake.