Green bearings or stock adjustable

I have never seen Green Bearings in any 8 3/4, ever, unless someone replaced them. All the way thru 74 when they stopped making 8 3/4 rears.
Well, then for some reason somebody put green bearings in an almost-new '70 Road Runner 8.75". The car didn't have 30K on it when I got it. My assumption was it was built that way.