Sorry, the stock bore size is 3.875". As for the bearings, the part # doesn't tell what undersize they are, this is only stamped seperately on the steel outer shell or ink stamped. Standard bearings aren't machine stamped as to their size, only undersizes have it on the bearings. So having no undersize on the bearings would indicate they are standard bearings. The pistons also don't have markings identifying them as standard bore, only if they are oversized.
