Installing my vortech in about a week and I'm making sure I have all the tools I need. I've done a ton of searching but I still can't find my answer. The installation manual says you need a 3/8" NPT tap, 3/8-16 Tap and Handle. The only kind of 3/8" NPT tap I can find is an 18. Is there such a thing as a 16 or does the 3/8-16 signify something else? Thanks for the input guys.