In a message dated 3/10/2004 11:05:59 PM Eastern Standard Time, greenbriergoon@hotmail.com writes: I am assembling a differential for my 4 speed conversion. I need to make sure I adjust the ring and pinion correctly. Is "Prussian Blue" the right stuff to use to see how the gears are touching? >>>>>>>>>> That will work just fine with a very thin film. Ken Hand