After a little internet digging for some info for you I've come up with this. Check this article out. The bump stops are the dead give away to which FLCAs you have. Looks like the "s14s" you were sold actuall are s13s. Sorry it took me a little while to find the info.

Swapping S13 FCA for S14 ones? - Nissan Road Racing Forums

Hope this helps.

-Royce