Yep, it came in different size rear ends too like, 10 bolt 8.5/8.6", 14 bolt 9.5" and 10.5", etc.Did the G80 come in multiple axle ratios?
Look at post #2, you ratio should have a GU or GT prefix but, there's no guarantee someone hasn't changed the gears before you bought the truck.there is no way to tell what yhe axle ratio is without jacking up the rear end, turning the tires and counting the driveline revolutions.