GMPP Stage 1 Upgrade Kit .... Includes: 42 lb/hr Injectors & Performance ECU Calibration. People ask me if you feel a power increase with Stage 1 .... You do ! When you hit 2nd and near 5500 rpm the car pulls like a bastard. Stage 1 is designed for peak horsepower and torque improvements, where as the Stage 2 kit is designed for improvement across a broad rpm range. The performance gain claimed by GM for the Stage 1 kit is 31 hp and 5 lb-ft of torque, and a 0.3 sec improvement in the 1/4 mile. Well, I decided to come over to the Stage 2 world, so I purchased GMPP Stage 1 to Stage 2 Upgrade Kit. The kit supplies a 77.9mm Pulley, Hub, and shorter Drive Belt. The performance gain claimed by GM for the Stage 2 setup is 36 hp and 18 lb-ft of torque, and a 0.7 sec improvement in the 1/4 mile. I thought Stage 2 would be enough, but I still craved more power, so I installed the GM Stage 3 PCM & 76mm pulley. (Updated Pictures Soon).