Aluminum Small 4-Barrel Intake to Big 4-Barrel Carburetor Adapter. This carburetor adapter will allow the installation of any of the late square bore Edelbrock Performer, Holley and Carter AFB series carburetors to be put on early 50's intake manifolds with the small (3-3/4" wide x 3-7/8" long) bolt pattern. Adapter tapers from the larger 1-11/16" diameter throttle blade bore down to the 1-7/16" diameter holes in the intake manifold. That eliminates the possibility of vacuum leaks due to the mismatch in the manifold port alignment. This adapter also will be correct for the early Carter WCFB and the smaller AFB carburetors with these port diameters. Adapter is 1/2" thick. Kit includes the studs, nuts, washers and gaskets.