I have a 1988 Baha Cruiser with twin 454's. The starboard engine quit last trip and has no spark. Both engines have DUI distributors. I've done some digging and believe I have a bad ballast resistor. From what I've researched that ballast resistors are mostly needed for points style ignition systems. With the newer DUI ignitions on the engines are the ballast resistors needed, or should I just go ahead and leave it on and replace it with a new one?