If you look at the replacement parts on Tower's site for the rear bearing on the 120AX, it says that it is the bearing for ALL engines from 108-160. Since the 140 falls in this category, they must be the same size. The descriptions are by different Tower employees, and not from the manufacturers.

I am glad to see the sealed bearing for the 140. After a few more gallons I'll throw my SS bearing in my 120.