Phenolic plastic will help keep heat out of the carburetor equaling more horsepower. Carburetor adapter aluminum fits for all square hole carburetors, for H-olley, E-delbrock, B-arry G-rant (D-emon) SB&BB , F-ord. The carburetor spacer is made of aluminum alloy, which is anti-rust, corrosion-resistant, durable and has a long service life. Carburetors With 1 11/16" Ports And Are 1/16" Thick. Please check the part number / model / make / year carefully before purchasing to insure fitment. YUCHENSHLP specializes in providing high-performance repair and replacement parts for various automobiles, we support 365 DAYS returns and exchanges. If you have any questions, please feel free to contact us, we will solve it for you as soon as possible, customer satisfaction is our unremitting pursuit.