For whatever my opinion is worth.......
it's different than the others. I suggest a crc gear lube that they make at an excellent price under their Sta Lube brand. It's api/gl-5 sae 85w140. It's works extremely well for everything and meets essentially every specification out there for anything because it's vastly superior to the gear oils (including the synthetic ones) you see on the shelf at discount auto parts. You can get it from napa just pay attention to detail to make sure you get the right one (there are half a dozen different Sta Lube gear oils). This is the stuff I use in my diffs:
http://crcindustries.com/auto/?s=SL2433