These -6 AN fittings are designed to fit in to the stock 5/16 inverted female brass adapters or connections that  are standard on all the early automatic transmissons and radiators.

P/N     11760       -6 AN male to 5/16 male inverted   $ 8.95  each

P/N    12065        -6 AN male to 5/16 male inverted    $ 17.95  pair