I liked using a cam cover vent to work with the oil separator on the side of the block.

Venting crankcase pressure from the head and from the block made sense: the separator box accessed the crankcase air space; the cam cover vent accessed the air space inside the cylinder head. Venting the pressure from both 'caverns' was logical.

But, venting from the cam cover had a problem. The air space inside the head under the cam cover is very much a vapor laden air space. Because the camshaft, and all eight of the lifter buckets, splash the oil around, creating a lot of oil droplets flying around inside the 'dome'.

Whereas the separator box provides a means of separating out the oil vapor and droplets that fly around inside the crankcase, and letting the separated oil flow back down into the crankcase, there was no corresponding separator/precipitator in the cam cover under the vent elbow.

I figured out how to address that shortcoming, and how to improve the vent flow by providing a larger flow path so that the velocity of the flow would slow down. Which would further aid the separating out of the oil vapors and droplets.

This pic shows the dual hoses coming from the crankcase separator box and the cam cover vent elbow. The hose underneath those two is the vent hose from the 'catch can' for the crankcase vent, going to the turbo air inlet hose.