[rynobuilt]

they should be 1/2" x 20 inverted flare, as in a 45 degree flair, like a fuel or brake line, you can most times use a off the shelf 5/16 brake line that already has the fittings on them at oreillys for your transmission cooler line. i just installed a champion radiator in a c-10 and did this. i have seen some champion radiators that didn't use the inverted flair, those will use an adapter that has 1/4 npt fittings to 1/2 inverted female. yours should be 1/2 x 20 inverted male looking
at that pics you posted...