PCV systems have been in common use for over 50 years, with a great deal of factory engineering involved in their research and development. Why not simply try to duplicate these successful systems rather than attempting to reinvent the wheel? GM chose to use a modified crankcase ventilator with a PCV valve adapted to it when they put a closed vent system on the 261, and that system is very easy to duplicate with only a little effort. Yes, I'd suggest making the intake manifold port for the PCV at least 3/8" NPT, and the 1/2" NPT manifold port like the big rigs with a hydrovac brake booster and a vacuum shift 2-speed rear end used would be better.
Jerry
