A Tighter rear diff will cause the car to push more though the corner (larger turning circle) but you will probably notice a slightly quicker accelaration out of the corner but again on power it would tend to make your car push wider than if the diff was on a looser setting.
I tend to run my rear diff slightly looser than the front, but tight enough to only
JUST slip under hard acceleration from a stand still.The front should not slip at all I.M.O
The car will be easier to drive if you allow your diff's to slip alittle
