Edelbrock Carburetor Adapter Plate
You need to have this to eliminate vacuum leaks when installing a square flange carburetor on an aftermarket intake with dual square bore/spread bore flange or for a spread bore carburetor on an Edelbrock intake manifold that does not have a regular mounting flange!
Edelbrock Square-bore Carburetor Adaptor Plate 1/16" thick
Square-bore to Spread-bore Adaptor Plate
Edelbrock Spread-bore Carburetor Adapter Plate 1/16" thick
Spread-bore Adapter Plate