Coil Pro Power Series GM LS1/Ls6 Engines 8-Pack 1997-2004 GM Cars W/Vin G/S 1998-2006 GM Trucks W/Vin E/D (8Th Digit) Additional 2-Pin Connector MSD IgnitionThe 2 pin connector must be plugged into the coil. If not, the coil will not operate. This additional connector is for optional ignition timing control. MSD's engineering team has been working diligently the past year to improve our Multiple Spark Coils for the GM LS engine platform. The coils fit in place of the OEM coils yet are capable of delivering higher spark energy to the plugs, topped with multiple sparks at idle rpm. Increased spark energy