will replacing my centre diff in my wrx MY98 thay has started to whine whirr in 1st and 2nd and also shuddering through the steering wheel whilst turning a corner sharply at low speed.
I have come across this for $600 Aust
Wrx 5 speed Cusco 65/35 centre diff

 

You will change the handling of the car quite a bit. The standard split with your viscous unit is 50/50 so the car should tuck in nicely when pushing around corners. With this unit the split will make it more tail happy just like a dccd unit which is tail out on corners. I would source a good viscous unit and keep the original split.