what is the difference between the lsd and the anti-spin diff.? we have a 2012 2500 ST 4x4 at work that lsd is on the option list on the window sticker and also a 2012 1500 ST 4x2 that has the anti- spin on the option list on the sticker. i jacked the rearend up till the wheels cleared the floor on both trucks and put the trans. in nuetral and turn the wheel on one side and the wheel on the other side turned the oppisite direction on both trucks. my knowledge on the older models is that they turn the same way on both sides on a lsd is this still correct?