Just be sure to use bearings from the same lot as you go. And congratulations for knowing about the grades of the bearings. Grade 25 is the top-end. Getting even lower-count bb's sends the cost through the rafters. It seems some tightwad shops use Grade 200, and argue that they are just as good. But I was taught to use the 25's way back yonder. And will continue to do so.
Happy Trails!