I'm still struggling to decide the best way to handle PCV on my rebuilt B20. I'm looking for the cleanest under hood experience possible, which means eliminating hoses. I've abandoned the crank case valve and hose that T's into the booster hose to the intake, and replaced that with a small K&N filter instead. It has worked well for 2500 miles (although getting black). I still have the valve cover cap with the vent pipe to the front carb filter, however. I originally left this on because of a discussion I found on Brickboard from 2008 where someone suggested that the crankcase really needed a fresh source of outside air blowing through it, and that it was best to leave a form of vacuum on one end or the other of the PCV system.

You can see where I'm going with this. I'd really like to put an old style filler cap with no vent tube on. This would allow both ends of the crankcase to vent to atmosphere, but without any flow through the engine.

So to take the debate to the next level, why do I need flow through the crankcase? The older B16's and B18's had the non vented filler cap and vent tube out the bottom without any flow assistance. Is there something about the B20 that is different? Are there health or longevity concerns if the crankcase doesn't get fresh air, or is PCV only for emissions?