Polished chrome-plated steel timing tab designed for big-block Chevrolet engines using an 8″ diameter harmonic balancer. Installs directly using the stock timing cover bolts with no modifications necessary. Features engraved degree markings from 16° before top dead center (BTDC) to 4° after top dead center (ATDC) for accurate ignition timing checks. The bright chrome finish adds a clean, show-ready look that complements chromed timing covers and other engine dress-up components.