http://jimwolftechnology.com/wolfpdf/BEARINGSELECTIONGUIDEGTIR.PDF
this should save some people massive headaches.
if you want to use OEM nissan bearings you need to have the 2 numbers off the crank and the number off the block as shown in that link.
when you have those 3 numbers you can give them to someone who knows what to do with them and they can tell you what grades of bearings you need to use.
takes out alot of guess work.
however, this is not a replacement for plasti-guaging… its just due diligence.