Moroso 64947 Moroso 4150/4160 Carburetor Spacer - Open Plenum - 1/2in - PhenolicMoroso 64947 Moroso 4150 4160 Carburetor Spacer Open Plenum 1 2in Phenolic 4500 Carburetor Spacer, Phenolic, 1 2" , Open Plenum Design Advanced phenolic compound, specially formulated to reduce heat conductivity 10 times greater than aluminum Reducing fuel temperature inside the carburetor results in a denser, more powerful fuel charge to the manifold Insulating phenolic spacers come pre drilled for alignment pins Gaskets not included *Not legal for