I used a 1/2 in hard line to -8 fitting for mine. I think it was a Russell fitting. I have an extra still in package in the garage I'll check the part# later. I just left a short piece coming out of the trans that wasn't rusted and used these because I already had them. Worked good and after a year still hasn't leaked. Are you trying to get rid of all the stock line?
Ok, I used a Jegs fitting part#100553. JEGS 100553 JEGS Hard-Line AN Adapter Fittings
. I believe the thread in the trans case is 1/2 npt. I also used jegs push loc hose and AN fittings. You want to use -8 because that is equivelent to 1/2 like your stock line. JEGS AN to NPT Adapter Fittings - JEGS
here are some AN to NPT adapters that would thread right into the case if it is 1/2 NPT. Hope this helps you out. Good luck with replacing the lines. I think I'm going to do the rest of mine since I have to work on the trans again anyways.