to my knowledge it is stock. in the dry, if i punch it from a dead stop it just lights the tires up. there is this curve i take on my way home from work about 20 mph and if i get on it about 3/4 of the way through i can get the back end to slide. in the wet i can get the tires to break completely loose on the 1-2 shift. it has 4.10's and all terrain style tires, probably cheap ones.