The Edelbrock Carburetor Spacer allows you to space carburetors above the intake flange to increase plenum area for more torque and horsepower. This wood carburetor spacer includes heat-insulating phenolic fiber. It insulates and tunes your carburetor and manifolds power band. This spacer extends the length of the intake mixture column to improve air and fuel distribution. There are two different styles of spacers with distinctively different benefits. The open plenum design increases plenum volume for improved high RPM power and the divided-wall design increases the air and fuel mixture velocity for improved low-speed and mid-range torque. This carburetor spacer comes with 0. 5 thickness and it fits dual-plane intake manifolds.