I did a bit of research into diffs a while back and the different options.
With plated diffs I think you've got the option of the Gripper type and i've heard that Mike
Rainbird might have knowledge of a new type that is a bit more 'user friendly' perhaps.

There is also the option of a Quaife diff and having your viscous LSD re-worked or even uprated by people like Bara. The standard Viscous LSD is quite mild to avoid too much understeer and in the interest of a forgiving nature. Chances are it might be not even providing the standard 25Nm locking action and be considerably less