There are a lot of boats fit with Chevy big blocks that are running EFI systems and to make installation of an MSD 6M-2 or 6-Offroad even easier we offer this new Harness! The Harness fits the factory style dual connector coil with matching connectors, then plugs directly into the 6-pin weathertight connector of the MSD Ignition Control. No cutting or splicing is necessary.