The 1999 model was the last Viper that had forged pistons. Subsequent years had lighter-weight, hypereutectic pistons similar to other sports cars, as well as, improved exhaust systems. Also in 1999, the American Club Racing (ACR) model was introduced. This model featured suspension and engine enhancements focused on maximizing performance in road racing and autocross environments. Horsepower was bumped to 460 bhp in these models. Continuing chassis refinements, ABS braking was introduced in 2001. In 2002, the end of second generation production was celebrated with the release of 360 commemorative "Final Edition" models. These models were painted red with white stripes, paying tribute to the famous race-winning Oreca cars.
Source: Wikipedia (original)