ARP Spark Plug Indexers

By allowing you to consistently position spark plug ground electrodes out of harm's way, these ARP indexing tools take the guesswork out of installing spark plugs where the combustion chamber and high dome piston clearances are critical. Designed to fit it the palm of your hand, these tools eliminate the need to perform cylinder head calibration. Best of all, the ARP indexers are made from aluminum alloy with precision-machined threads that allow you to proof the quality of spark plug threads before installing them in expensive cylinder heads. They're anodized for protection and quick recognition and designed for use with tapered gasket 14mm plugs. Show Less