The Edelbrock 4-Barrel Phenolic Carburetor Spacers are used where more plenum volume or more carburetor-to-plenum floor distance is required. It allows you to space your carburetor above the intake flange to increase plenum area for more torque and horsepower. This high-tech, 4-hole, black, phenolic carburetor spacer is 1 inch thickness and can withstand extreme temperatures. The 4-hole spacers enhance low-RPM torque and throttle response and dampen reversion effects on the carburetor.