This document provides instructions for using a service manual for GM V8 454 cid and 502 cid marine engines. It begins with an introduction on how the manual is organized and numbered. It then provides directions on reading parts manuals and understanding references like part numbers and quantities. The document outlines key information like engine serial number locations, proper water testing of new engines, and factors that influence boat and engine performance such as the boat bottom, marine fouling, weight distribution, and climate.