8 3/4 rear end question

Dana67Dart nailed it. He's exactly right.
Depending on how accurate your observation was, either 2.94s (very much highway gear) or 3.23 (a pretty good compromise ratio.)
Either are considered high gears (low numerically).
Low gears, meaning low car speed for engine revolutions would be 4..11, 4.56 etc (higher numerically).