Ford AOD cooling line thread size

[IC2]

I am installing a 1988 Ford 5.0 with an AOD in my 32 Ford. Starting to install a remote tranny cooler and looking for help on what size thread is in the tranny case. A 1/4 NPT seems to go in finger OK tight but I am not totally sure this is the correct thread to use. Any help will be appreciated.
Thanks

My recollection is that most of these are 1/8" NPT, though many Fords of this vintage had whatever worked that day for many 'odd' parts.