The Edelbrock Four-Hole Square-Bore to Spread-Bore Carburetor Adapter allows proper installation of carburetor to manifold. It mounts the Edelbrock square-bore carburetors to stock Quadra jet and Thermo-Quad manifolds. It is designed to replace the original equipment unit. It allows the use of almost any carburetor on almost any intake, saving the hassle and expense of purchasing all new components when changing carburetors or intakes.