Here is scanner data as we test at idle with PCV, stock, stock modified with a smaller hole and the orifice only type.

As seen stock PCV used was leanest at idle, then reducing the hole size of stock PCV from 5/16 inch to 3/16 less rich and then with orifice type richest idle.

PCV flow then effects fuel trims.
We'll test the modified stock PCV for awhile and see if it effects less oil flow into intake, any negtive to engine seals and gaskets and what effects to air/fuel.

Stock orifice type of GM's used 2003 pickups I think the hole is too small and I think the pintel value is safer.