1968-1971 Starter Motor To Frame Ground Cable GC6871
Without a ground cable on your 1968-1971 Corvette, you can run into multiple ignition, charging, and elecrical system issues. The ground cable is responsible diverting any electrical interference away from other components. 
#2 Gauge
13 1/4" Lug to Lug
 
                  
                    
           
                    Also known under these part numbers: (For reference only)