This manual covers Indmar GM V-8 Inboard Motors manufactured between 1983 and 2003. These engines are known for their robust construction and reliable performance, utilizing the proven GM V-8 platform in various displacements, including 305 cu in (5.0L), 350 cu in (5.7L), and 454 cu in (7.4L). Designed for marine applications, these naturally aspirated gasoline engines typically produce between 200 and over 400 horsepower, featuring either carbureted or early electronic fuel injection systems and either raw water or closed cooling configurations. Their durable design and adaptable nature have made them a staple in the marine industry for decades. This comprehensive workshop service repair manual in English provides detailed instructions for the maintenance, repair, and troubleshooting of your Indmar GM V-8 Inboard Motor. It covers essential procedures such as routine checks of spark plugs, belts, and impellers, as well as fluid capacity information and recommended service intervals for tasks like oil changes. The manual also includes diagnostic procedures to help identify and resolve common issues, ensuring your engine operates at peak performance and longevity. This resource is invaluable for owners, mechanics, and technicians seeking to maintain and repair these engines effectively.