Looking for an original 71/72 8.5" posi 10-bolt rear with 3.08 gears. It must be the Oldsmobile housing with the "O" casting, not the "A" for the Buick housing. Thank you

Thanks Fun71 for pointing out the error in my thread. Hopefully the correction is now understandable.

 

You have a bit of incorrect info there. The Type-O rear was last used in 1970. I think you are looking for a period correct 8.5" 10 bolt corporate rear instead of a Type-O rear, which is a 12 bolt cover/10 bolt 8.5" ring gear.