Dorman makes repair kits for them. You can also tap and install a fitting. I suggest a plastic fitting and get the liquid teflon thread sealer. Do not over tighten or you WILL crack the neck. Ignore the non mechanics saying it’s pressurized and you need a new radiator. It’s just an overflow line.

You may have to grind or file a flat spot on the stud coming out to get clearance. Dorman has studs with flats already in them for easier installation

Most AWD systems have tolerances. It’s usually pretty small like no more than 1/4" difference in circumference.