B&B Performance Spark Plug Indexing Shims

B&B Performance spark plug indexing shims properly align your ignition spark with the intake valve, adding increased horsepower. These soft copper gaskets are available in three thicknesses per set, allowing you to adjust the electrode's location when the spark plug is torqued in the cylinder head. Positioning the spark at the most advantageous location will provide a performance improvement. The shims are available in different sizes, for flat or tapered spark plug seating.