UPS guy dropped off some stuff a little bit ago. My O2 extensions came in as well as another Sean Hyland book. it's called High-Performance Mustang Builder's Guide 1994- 2004. it really goes into good detail to guide you through your build. there's a chapter dedicated to each aspect of the car: Chassis, wheels and tires, suspension, brakes, engines (3.8, 5.0, 5.8, 4.6 SOHC, 4.6 DOHC and 5.4), transmission, rear end, aerodynamics and safety equipment. he even shows you how to get involved with organized track racing and shows some of his project cars. i recommend this book to anyone with a 94- 04 Mustang...