This Service Repair Manual covers GM V8 Marine Engines, specifically variants #23 from the 1998, 1999, 2000, and 2001 model years. These engines, featuring V8 configurations with displacements of 7.4L (454 ci) and 8.2L (502 ci), are equipped with Electronic Fuel Injection (EFI) and Multi-Port Fuel Injection (MPI) systems. They are designed for marine applications and utilize either seawater-cooled or closed-cooled systems. The manual provides detailed information on engine specifications, including ignition and charging systems, as well as power steering. The purpose of this comprehensive 1027-page English-language manual is to provide essential guidance for the maintenance, diagnosis, and repair of these marine engines. It includes detailed troubleshooting procedures, diagnostic information for MPI models, and technical specifications. This resource is invaluable for owners, mechanics, and technicians seeking to ensure the optimal performance and longevity of their marine propulsion systems. The manual is compatible with Windows, Linux, and Mac operating systems and is available as a digital copy.