Mercury - SC1000 Speed Kit 80 MPH Speedometer & 7K Tachometer Dual Engine Black Face 79-8M0185893. Overview. The Mercury SC1000 Speed Kit (79-8M0185893) is a complete SmartCraft gauge package for dual-engine boats. It includes an 80 MPH SC1000 speedometer and two 7000 RPM SC1000 tachometers, both featuring black faces, white numerals, and glass lenses for that clean, factory Mercury look. Built for SmartCraft systems, this kit provides smooth, accurate readings for both engines - giving you the