BBK Power Plus 58 millimeter Throttle Body for GM LT-1 for all BBK 1992-1993 LT1 5.7L throttle bodies are designed to increase airflow and improve horsepower from between 7-12 HP depending on the vehicle and application. All BBK performance power plus series throttle bodies are CNC machined from high quality 356 aluminum castings to ensure perfect OEM quality and fit every time.