After some research and parts comparison it looks like either the 4C or 4B kit will work with the base model diff and the sport package VLSD. From what I can tell the 4B kit has the new axle stub part number which is compatible with the Sport and base. The 4C shows the axle stub as just the older part number fitting the Nismo/sport. I ordered the 4C kit yesterday because the axle stub parts matched the Nismo stock stubs so crossing my fingers.
