Your forgetting another G-body the 8.5" rear-end came in.
The 1984 Hurst/Olds. It's the one with a Grey upper body, red stripe kit, and Black lower. The 1983 H/O came with the 7.5" rear-end, and was Black on top, red stripe kit, and Grey on the Bottom
So here is the revised list:
1984 Hurst/Olds, 3.73:1 ratio, posi optional.
1985-1987 Oldsmobile 442, 3.73:1 ratio, posi optional
1984-1985 Hot-Air Turbocharged 3.8L Regals, 3.42:1 posi optional
1986-1987 Cold-air Turbocharged 3.8L Regals, 3.42:1 posi optional
Ryan