THESE ARE FOR OLDSMOBILE ENGINES . DESIGNED TO HELP SLOW DOWN OIL TO THE TOP END  . THIS PRODUCT IS DESIGNED TO KEEP  FROM  OVER OILING THE TOP END AND HELP KEEP FROM PUMPING THE OIL PAN DRY . THESE ARE MAINLY DESIGNED FOR HIGH RPM MOTORS  LIKE JET BOATS , RACE ENGINES , OR RUNNING ROLLER CAMSHAFTS . YOU CAN ALSO INSTALL THIS PRODUCT FOR SIMPLY IMPROVING THE OIL SYSTEM . WILL WORK FOR ALL APPLICATIONS . THIS IS A SET OF 4 . WILL NOT FIT 403