there are standard size bearings, ones that are 20 thousandths over sized and ones that are 50 thousandths oversized. if you spun a bearing and need your crank machined then you will need oversized bearings.
a set of four new from mazda is $125, my price is $79 shipped for a set in any size
i have talked to more than a few techs and rebuilders here in town and they do not feel, even at higher numbers, that anything other than stock bearings are required. just fyi
really? why is that? I did hear to get after market ones if you change redline and also because there is more/less of a tolerance, cant remember which though.