2E engine toyota replacing AISIN Water pump

AISIN Water Pump have 6 impeller while GMB water pump have 7 impeller. The problem in my old water pump is it have a noisy sound bearing but no water leaks. トヨタ 2E エンジン Aisin Seiki Co., Ltd. (アイシン精機株式会社 Aishin Seiki Kabushiki Kaisha) August 1-2011