Changing the lengths of the links does have an effect on the anti squat, but it will rat out the uni's and the effect is not enormous. This was discussed in another thread with pics of the roll centres etc for 4 link rears.
Another issue, putting solid bushings eg rose jonts or urethane in all of the 4 link bush points creates a swaybar effect with the diff acting as a swaybar during roll. I'd draw it but i only have paint and its rubbish.
