I have a T5 from a 1985 S10 and it's definitely 1:1. Must be a typo.
5th gear varies. Most of the T5s that went behind a V6 had steeper ratios and work better behind a stovebolt. Many of the 4 cylinders had a 0.86:1, which is hardly worth shifting into.
0.72 and 0.73 are pretty common. Here's a list that might be useful....there are others if you do some searching.
T5 Transmissions 
