The 69 GTO I picked up has a rear end with the converging ribs. THe casting number is 9795084 with a /249\ below it. On the other side is a CFD. What does this tell me? I looked high and low, and found nothing specific. Previous owner told me it was posi. I can't find any other markings and I have yet to open it. It does have a tag that states to use a specific fluid only bolted to one of the cover bolts? Also, when I turn the passenger side wheel, the drivers does nothing. When I turn the drivers side, the passenger side follows in the same direction as the driver side. Not posi?