length is the same… 12mm and 14mm refer to the thread pitch of the inner tie rod end where the outter threads over it.
S14 tie rods are the larger diameter and will fit on an S13.
i use S14 on my car and in the future i will only be ordering and selling S14 tie rods sets whether you have an S13 or s14.
i bent both of my OE S13 tie rod evenly just from braking so hard from high speed at random… cause it’s fun.
