The discussion centers around recommendations for books on engine building and modification, particularly for off-road motorcycles and classic cars like the El Camino and Chevelle. Participants emphasize the importance of selecting books based on specific interests, such as fuel injection, carburetors, and engine efficiency. Key titles mentioned include "How to Hotrod Your Big-Block Chevy," "Performance with Economy," and "Engine Management - Advanced Tuning." The conversation highlights the value of diverse sources, noting that even books on different engine types can provide useful insights. There is a focus on learning about EFI, ignition programming, and airflow optimization, with suggestions to explore works by authors like Greg Banish and Philip Smith. The importance of synthesizing knowledge from multiple books to build a comprehensive understanding of engine mechanics is also stressed. Overall, the thread underscores the wealth of resources available for aspiring engine builders and the continuous learning process involved in the craft.