The ILFR6GE Laser Iridium series plugs come pre-gapped as specified by your engine manufacturer. Always check the gap prior to installation. Use only the spark plug listed in your engine owner's manual. Using the wrong plug can reducing optimum performance, reduce fuel economy or cause damage to you...

Spark plug set 863656A1 is for use on V-8 MerCruiser stern drive and inboard engines (5.0L, 5.7L and 6.2L MPI) with ECM 555 (serial number 0M300000 through 2A455878). The Quicksilver brand is the leader in delivering uncompromising engine oils, parts and accessories to the marine industry for over 6...