if you're changing to an aftermarket cooler I would go with a
-6 an fittings. The transmission will need 1/8" npt to -6 jic adapters. These are so much easier to work with than the factory style lines.IMO
Shoulda wrote that in bold and underlined it!! Best thing you can ever do when doing it from scratch, easy, touch more fluid capacity dur to larger ID of line, guarunteed no leaks, ever. Easy to make and install...other than inital price point it's a serious no brainer. Wanna get really fancy install some Jiffy Tite fittings on the lines coming off the tranmission so if you ever do need to pull it, you uncouple the lines just like a air coupler...just be sure to reverse the female and male on the input/output line...not that it will really matter but it's just something that makes life easier since you can easily identify the input/output of it.
I switched literally every connection from cooling, to brakes, ******, etc...over to AN style and man what a piece of cake it was to work on after that.