I'm thinking of adding a plate transmission cooler in sequence after the existing one - but I can't find any information as to the size of fittings so that I can run a hose from the outlet to the add-on cooler and then back to the return hose. Quick connect ones would probably be best.

Does anyone have the information AN or NPT? AN 6, NPT 3/8? I suspect AN -but I wouldn't know one if it was sitting beside me.