Transmission Cooling Line Fittings

They are either 5/16 inverted flare (brake lines style) or 5/16 SAE flare, otherwise known as no. 5 SAE

That is NOT the same as no5 JIC or AN

Newer "metric" stuff like my 97 White Whale or the Dakotas are different. I have not figured out, yet, what they are.

If you Google "specifications of inverted flare fittings" or .....of SAE flare, you can find charts etc detailing them:

http://www.muellerindustries.com/uploads/pdf/45 Flare Fittings.pdf

http://www.ite-tools.com/pdf/en/6-1-1.pdf