Skunk2's Pro-Series Intake Manifold improves airflow thus increasing horsepower by as much as 8% over stock manifolds on stock engines and even more on modified or forced-induction engines. Skunk2 manifolds significantly increase horsepower between 3000-8800 rpm. The new Pro-Series design features a 22% increase in power over the previous design. Choose the Skunk2 Pro-Series manifold for a simple bolt-on installation that delivers maximum power. Ideal for NA and Forced Induction! *(Skunk2 B Series Intake Manifold 1994-01 GSR(B18C1)*