The first LS1s were released the year after the limited-run LT4 debuted, which at that time was the modern marvel of the SBC world. In retrospect, the LT4 didn't last long before being dethroned. While the differences between the Gen-II LT1 and LT4 were mostly external compared to the traditional small-block 350-cubic-inch, the Gen-III used all new architecture and components. Therefore, there are no carry-over parts between the Gen-III and its predecessors.

The all-new fifth-generation Corvette received the new LS1 engine package in 1997, while the F-body platform (Camaro and Firebird) got it the following year. The 1997 Corvette's 5.7-liter LS1 was rated at 345 horsepower, and the 1998 F-body 5.7-liter LS1 was conservatively rated at 305 horsepower. Ironically, there are minimal differences between the two, considering the huge horsepower rating difference. The horsepower rating was either underrated due to insurance issues, or it was thought that the Corvette was given the higher numbers to justify the $20,000 price difference. Since then, there have been many improvements and refinements to these engines. The 405-horsepower LS6s, 505-horsepower LS7s, and 638-horsepower LS9s are the most impressive advances. Trucks, SUVs, and some front-wheel-drive passenger cars even have variations of the LS-series engines.

The LS1 is much different from its elder small-block Chevy and LT1 siblings in all aspects. Despite the unfamiliarity and new-ness, it didn't take long for the performance world to take notice of the huge performance potential of this engine family. The LS1 has proven itself as one of the most responsive modern engines when it comes to performance modifications. It responds with glee to just about anything you throw at it, like a loyal pet given a treat.

The first few modifications came along fairly slow as there was a steep learning curve early on. There were a few homebrew modifications, such as ported throttle bodies, ported mass airflow sensors, and (gasp!) gutted catalytic converters that woke up the engines well. Before long there were cold air intakes, under-drive crankshaft pulleys, and headers and exhaust systems. Then came camshafts, ported cylinder heads, intake manifolds, nitrous systems, turbos, blowers, and so on. It all complements the Gen-III and -IV engine family very well. There seems to be no wrong way to build one of these setups, although some choices do perform more efficiently than others.

You will find information related to the engines as a whole in this book, listed as "LS-series" throughout. Specific differences and changes per engine family will be isolated by specific name. The GM performance parts LSX block is listed as "GMPP LSX" when referring directly to that engine block. Also, when referring specifically to small or large power-adders, I would use the mindset of "small" being something the original equipment manufacturer (OEM) engine would handle. For N20 this would be 150 shot or less with the proper safety precautions and fueling. With boost, I would classify "small" as what the supercharger or turbocharger kit does in off-the-shelf form. If it produces 7 psi as supplied, that is what I would consider "small." Large power-adders are anything above these as-supplied basic numbers and would normally require greater attention to specific areas of the engine buildup for durability or longevity.

Nowadays, there are many choices to be made in how you wish to modify your LS-series engine setup. You can build all-out heads and cam setups on everything from a stock 5.7-liter short block to monster displacement 454-plus-cubic-inch engines. The LS-series engine remains a developing performance architecture, and constant progress is being made, seemingly daily. In this book, you'll find information on many setups patterned to build your LS-series vehicle to your desired power level, from basic to extreme.