Mercury - SC1000 Tachometer 7000 RPM SmartCraft Analog Gauge White Face 85 mm 79-8M0135634. Overview. The Mercury SC1000 7000 RPM Tachometer (79-8M0135634) blends SmartCraft accuracy with a clean, classic gauge design. It fits a standard 85 mm (3-3/8 in.) dash opening and features a crisp white face, black markings, and a glass lens for sharp visibility in any light. This tachometer provides smooth RPM readings and integrates seamlessly with your SmartCraft system - including SmartTow and advanc