If it's a ke70 it wouldn't have an S series Diff stock, although some trim models (maybe the XX) came with an S. Most likely it's the run of the mill Borg Warner. Incidentally most people will argue the BW is far stronger when locked compared to the S.
Also OP, LSD options for the S are as rare as to be non-existent as the BW.
You could look at Tarago For series diffs. Plenty of LSD options (ma61, is200).