Well.. differences are..
MP7.5 is the standard kit.. Kanai is the fully upgraded version
these are most of the differences.. mp7.5/kanai
dogbones in in center of car/ universals in center of car
dogbones in rear/ universals in rear
plastic radio tray mounts/ aluminum radio tray mounts
plastic wing mounts/ aluminum wing mounts
orange and silver aluminum parts/ blue hardened aluminum parts
silver chassis/ hard anodized chassis k3, has a milled lighter chassis
standard diff in front/ LSD diff in front K1 had lsd in center also
regular motor mounts/ blue finned motor mounts
regular antenna mount/ special blue antenna mount
bushings in steering/ ball bearing steering
17 degree hubs in front/ 20 or 22 degree hubs in front
3.0mm shocks and shock shafts/ 3.5mm shock shafts with teflon coated shock bodies
silver or black springs/ blue springs
black plastic shock pistons/ white pistons
thats pretty much it.. can't really think of anything else.. other than kanai comes with all the pretty blue washers, and stuff like that too..