RBS carries this handy fitting for the racer to connect on the back of a gauge that uses a .125" male pipe thread and connect a AN hose to it. Made from billet alum. and anodized for corrosion protection.
Threads in the fitting are .125" NPT and the racer has a choice of -3 or -4 AN for their line fitting. Hex on fitting is .562".
Racer can choose from drop down menu fitting size.