[Pontirag]

race bearings are often of a harder material than street bearings.

softer bearings are used on street applications where there will often be more dirt or grit in the oil. the grit or dirt will imbed itself in the softer bearing material rather that score the crank. Most GM products used the softer bearings on origional applications because to get an engine absolutely clean during the assembly process is vertually impossible.

an individual building a race motor can spend alot more time getting the parts spotlessly clean and changes his oil quite often . Veru rarely will dirt or grit get into a race engine.

race bearings come in alot more sizes than street bearings