[asid61]

If you are doing a press fit, the best way is to give the part to the machinist and let them decide. For example, the vex bearings we recieved this year were actually about 1.124" in diameter, which would have ruined the press fit.
Unless you have a really good sheet metal guy, you might get holes that are +- ~0.002", which will ruin a press fit. Plan on reaming or locktiting any bearing holes in sheet metal.