does anyone know about special 10 bolt type O with type O raised on each side of rear chunk and larger axle bearings at ends of tubes.

 

Sounds like the 71-72 8.5" 10-bolt.They made two different castings.One with the large O's on each side of the pumpkin,facing the front,and the other casting had A's in the same location,along with a large "A" on the top.The O-casting takes the round cover,with the protruding lip that runs from 12:00 to 3:00.The A-casting has a cover that looks like the BOP 8.2" cover,with notches at 9:00 and 3:00.
The normal 8.5's take the SET-9 axle bearings,but if the rear is from a Vista Cruiser,then it has the larger SET-10 bearings,and thicker axles.