Yo Shanks,
here is a link for the grease i use:
http://marinestore.co.uk/SSSCX6007.html.
Never had a problem with leaking diffs since i used this stuff
For the amount you need to use on your diffs this stuff will last you years. You racing at Bury this Sunday? Think im coming along but cant decide between Bury and Stotfold?
Craig Collinson