GM 8.5" GM 8.625" differential bearing options

on the GM 8.5" and GM 8.625" there is sometimes some confusion over wich differential bearings and races to use , the 1999' and older ( any truck with rear DRUM brakes ) use the smaller OD 2.89" bearings and races , LM102911 x 2 , LM102949 x 2 , the 1999' and newer trucks use the larger bore bearings and races , LM603012 x 2 , LM603049 x 2 , these are the trucks with rear disc brakes