This book is really good to provide an overview to the subject of cylinder head modifications. The text is quite clear to understand but the book is generally introductory in tone and content. This book will suit a DIY enthusiast and someone wanting a better knowledge base. A trained professional will find this book too "basic" and therefore should consider other options. The book is well ilustrated and has some helpful case studies of popular heads such as pinto, Xflow, A series, Essex V6 and Rover V8.