Hey Dynamic88, I don't know much about rearends but you might want to try to retighten those bolts. Maybe they are just loose since you just put the cover on.
Now I will make myself look stupid.
Jim, could you give me a quick rundown on the different types of rearends GM used in Oldsmobiles from the 50s to the 70s. I have heared people refer to the type O rearends. What is a type O rearend? I know what 10 bolt and 12 bolt rearends are. Are the Olds rearends different from Chevy rearends? Or if you have a link to a good website that would work too. I just don't know much and I want to learn.