my mate is into the nissan drifty things, he has recently "shimmed" his viscous lsd, by putting a thicker spacer between the coupling and plates, effectivly increasing the pre load on the plates. TBH it behaves like a welded one, usual skittering when parking or making a tight turn. But he assures me you can get it in between with a thinner disc. He drives this car daily with no probs though. ill see if he has a post on sxoc about doing it.