First book to specifically address performance modifications for the LT1/LT4 engines Both are excellent platforms for affordable major performance improvements Features performance projects for the street, strip, and endurance racing engines Few engine builders have as much experience of the LT1/LT4 as Myron Cottrell In 1992, General Motors introduced the LT1 V-8 engine. This upgraded design, based on the traditional (since 1955) small-block V-8, marked a significant step forward for GM, as the engine was designed to be a modern, efficient, computer-controlled powerplant from the start. This was unlike any other V-8 GM had ever built, and the results were outstanding. The LT1, along with its more powerful stablemate, the LT4, raised the bar for performance-oriented small-blocks until the introduction of the LS1 in 1997. The LT1/LT4 engines are powerful, relatively lightweight, and affordable. They powered Chevrolet's legendary Impala SS (and thousands of similar police cars), Corvettes, and Camaros and remain viable choices for enthusiasts today. This book investigates every component of these engines, discussing their strong and weak points and identifying characteristics. Upgrades and modifications for both improved power production and enhanced durability are described and explained in full. All relevant factory casting numbers are listed. Aftermarket component upgrades for improved street and track performance are defined clearly and in great detail.