male to male... 1/2 npt to -10an or -8an.. You can also use a 3/8npt if you want to use something smaller then 1/2". -12an is way to big for a drain line

 

not really. it all depends on what space you have to work with. if the turbo is mounted low and the return does not have that much of a downhill slope, -12an can be beneficial and not considered overkill.

edit: i understand most are using smaller 62-67mm turbos on here with -3an feed lines where -10 should be more than enough...so yes -12an is larger than needed.