I'm currently running a f-body radiator + external trans cooler and since i put my big front mount on its cut off airflow to my cooler which is mounted in between the fm and radiator. I want to run lines into the radiator trans cooler first then into the external but don't know what fitting i need to do this. I want a fitting that will allow me to run AN fittings which i've already ran to my current external cooler. Does it need to have a o-ring?