Use the TA 1246 thin adapter/mounting plate when using a square bore type carburetor on intake manifolds that are machined for a spread bore type carburetor. Such as TA 1201, TA 1205, TA 1207, TA 1210, TA 1211 and TA 1235. Made from steel about the thickness of a gasket. Does not compromise hood clearance. Does not work on stock intake manifolds.