I believe the original steel tube from the PCV to the Intake manifold was 7/16" outside diameter. The threads on both male fitting nuts were 7/16 NF. That size tubing was not easily available to me at the time. I replaced the tubing with 3/8-inch OD having male fittings with 3/8 threads, cut off one fitting, bent the tubing to match the original shape and changed to an appropriate brass fitting in the intake manifold. For the end into the PCV valve I purchased a 90-degree hydraulic hose fitting with a 7/16 NF (-7) male inverted flare on one end and a 3/8-inch barbed hose fitting on the other. The hose fitting had a metal shield over the barbed tube that was cut off. I used a lathe but it could be cut off other ways. Then used a small fuel/oil tolerant hose to connect the pieces.
