ATI Pulley - Alumt - 2.41 - 10 Grv - GTO 5 Percent UD

This is an ATI 5% underdrive crank pulley designed for the GTO. It's made from aluminum and features a 2.41-inch diameter with 10 grooves. Installing an underdrive pulley like this can help reduce the load on your engine's accessories, potentially freeing up a small amount of horsepower and slowing down the drive system. This can be a popular modification when building a performance GTO.

The aluminum construction helps keep the weight down compared to a stock steel pulley. The 5% underdrive means the accessory drive system will spin at 95% of the crankshaft speed, which is a mild reduction that typically doesn't cause issues with charging system output or overheating. This pulley is designed as a direct replacement for the factory unit, making installation straightforward for someone familiar with working on the GTO's engine bay.