In that case Mobil 322 would be fine for your application. Base Oil Stock Viscosity really only becomes a factor when the grease is applied via an automatic lubricator system.
For high-performance greases for use in an automatic system the first thing you look at is the NLGI Number to see how pumpable it is, taking into account the ambient climate conditions where the machine in working. For example in a desert you might need an NLGI #2, in the middle of Siberia you might need an NLGI #00 or even 000 to make it pumpable. Then look at the results for the 4-ball weld test and the scar test. The higher the value in 4-ball indicates a grease more capable of supporting heavier loads than one with a lower value, for the scar test the shorter the scar length the more capable the grease is of maintaining a lubricant film before breaking down. Low-speed high-load applications generally need 5% moly and the size of the moly particles can also be a factor, the smaller the particle size (in general terms) the better.
