Use your recommended weight LSD Oil, something around the 80W140 range then add Penrite Limslip addictive to reduce the chatter.
Alternatively, Penrite make a decent LSD oil that supposedly has a heaps of friction modifiers in it already:
http://www.penriteoil.com.au/products.php?id_categ=4&=&id_products=377
I'm a little tight, so I just use Nulon SAE90 with added Limslip to keep the diff quiet and often dump the diff oil at the same time as the engine oil.