ALSO I have another question while I'm here. What kind of fitting is on the nozzle itself? It looks like a NPT type fitting. Wouldn't it be easier if it was a 3AN fitting?
That is correct for the jetting. The nozzle is actually an AN fitting, the reason it doesn't have a taper on the end is because the nitrous jet is the flare part of the fitting. The line seals on the jet.