Spectre's Carburetor Spacers insulate the carburetor from the manifold to keep incoming air and fuel cooler. This open plenum spacer is designed to increase the intake manifold's total area, helping to improve mid and high-range torque. Manufactured from heat insulating phenolic material, this 2 inch spacer includes gaskets and hardware to ensure easy installation. Spectre s Carburetor Spacers insulate the carburetor from the manifold to keep incoming air and fuel cooler. Manufactured from heat insulating phenolic material; this 2 inch spacer includes gaskets and hardware.