I'm not an expert, but I would assume that you should strive to have the cable perpendicular to the ground if you want to simulate deadlifts, i.e. move closer to the lower pulley, pull the handle bar straight up and make sure sure it touches your shin (while the cable is straight up). The handle bar is bound to be higher than your average barbell, so you would simulate elevated (?) deadlifts, i.e., where the weight is higher than the floor. Should be easier. You can probably lift more than what the weight stack gives you.