You'll want to look for the later 4x4 S10s that have the 4.3 V6 in them, they're more likely to have the higher gear ratio. The older ones with the 2.8 or 4 cylider will most likely have a 3.73 or 4.10, with the 4.10 being very common.
Or for the best overall S10 axle, look for a '98-'04 with the ZR 2 package, preferrable a 2 door Blazer or 4 door cab pickup. Those use a narrowed version of the full size truck axle and most also have the rear disk brake option.
