The Ford and Holden diffs are set up pretty loose from factory. I like to pull out the centre and shim up the cones for a more locked effect

You would be surprised at the difference. ANother hint with LSD is to avoid tight turns as these wear the friction cones over time.
If I am right, the cones do not load up when wheel speed differences occur in the reverse direction (ie, when reversing the car).
Maybe someone who knows these diffs better than me can comment! :confused: