8 3/4 venting oil from the vent. seems odd.

Here's where we are to date.
1. I assembled the rear and filled it to the point of oil coming out of the hole..
2. I drove the car on the interstate for a short run.
3. A small quantity of gear oil appeared to have come out of the vent located on top of the left axle housing when I got home.

4. Today car on "level" ground I pulled the plug and got at the better part of a quart out. At least a half quart or more.
It got down to a trickle, almost a drip and I reinstalled the plug.
5. I will again test the car on the interstate and report the results.

489 and original, matching parts.
B body.