PSweeney, With the hubs I make, I use bearing number 1628ZZ , ZZ is metal shielded/ sealed bearing, because it has less rolling resistance, and it has an OD of 1 5/8 [ 1.625] and 5/8 ID. When I rebuild show car wheels using no longer made hubs I have had to make a OD spacer of .0625", or you could get a smaller bearing R10, with a 1 3/8" OD and make a larger spacer. Or bearing number 6203 ZZ with a 40mm OD = 1.574" .
If you have found a larger OD that would make you machine to a larger OD, and you don't want to take the wheel apart, you could machine out the hub using a mill, not a lathe .
I hope this helps,
Jon Hansen, Hayden Wheels, 800-624-3803, 805-444-4489