RS5F31A is an open box, however it may be possible to fit some aftermarket LSD.
RS5F31V is a factory viscous LSD.
The version that came in the K11 had quite short ratios. The K11 did not have the 31A only 31V.
N14 or N15 31V versions had taller ratios which would give a much more relaxed cruise on the highway. The 31V was an option for those powered with GA16DE, which can be fitted to the CG.