Daytona Twin Tec High Output Coil For Carbureted Harley Big Twin This high output coil designed for aftermarket and OEM ignitions. Greater than 50 mJ and 40,000-Volt output for demanding performance applications. Features: Coil is for carbureted Twin Cam OEM single-fire design 45,000V Ignition coils exceed OE specifications For optimal performance use 381-656 or 381-703 plug-in ignition modules or stock Twin Cam ignitions Replaces OEM 31655-99 (will not fit in place of OEM 31639-99)