I thought the magic number was originally 390, but for some reason I 2nd guessed it when I looked at this thread.
With that said, we can achieve a proper ACC rating, 300+ DET and moderate CRIT whilst maintaining our 390 SS with the following:
http://ffxiv.ariyala.com/OZH1
564 ACC
469 CRIT
340 DET
398 SS
Flint Caviar HQ is used.