Oblithian

Sorry I can't reply to FAQ posts (it's a category mostly for repeat topics to be moved to, not new topics) you should put it in the apropriate other area, if you want responses.

In general though, once the system is pressurized the ID doesn't matter a lot, (unless it is too small) as long as it can maintain your maximum flowrate (more so the lines feeding it). The biggest issue you may face is your pressure regulator positioning. I am putting mine in the middle with two feed lines. Some people have reported issues with uneven pressure if the fuel pressure regulator is too far from the inlet.