Noticed this blob on the rear axle housing - factory or someone else's graffitii? '69 Z28; 04B LA Built car. BV 0403G1 Axle code....
(http://images5a.snapfish.com/232323232%7Ffp63579%3Enu%3D67%3B%3A%3E35%3A%3E257%3EWSNRCG%3D34%3A6895%3B86348nu0mrj)
(http://images5a.snapfish.com/232323232%7Ffp63584%3Enu%3D67%3B%3A%3E35%3A%3E257%3EWSNRCG%3D34%3A689%3C%3A%3C9348nu0mrj)
Hans, I didn't find any marks on the front of my diff. But I did find an orange spot on the back next to the cover and purple paint inside the yoke under all the grease. I think maybe to verify pinion nut torque.?? Check those areas also.