Yep, sure is, Just got my diff all done for the V8 car, and used the blue gel "Prussian Blue" and it worked great. Good Luck! Ryan Counterman, VP~WMCC VairKing@hotmail.com '65 Corsa Coupe V8 Kelmark; '65 Monza Convert 110/4sp http://f2.pg.photos.yahoo.com/vairking <<<<<<<snip>>>>>>>> > Is "Prussian Blue" the right stuff to use to see how > the gears are touching? > > Charles