It's not a major point but I would like to point out that the oil vent line should probably not be longer than 2 inches. The reason being that the crankcase "breathes" with the up and down motion of the piston. If too much tubing is used the accumulated oil will be sucked back in.
Because of the blow buy the net average pressure of the up and down cycle is not 0. You can safely run the line as long as you want. If over a few inchs you will see oil slugs that pulsate back and forth, but they move back more than forth, and after a few seconds exit out the tube.