If you replace the 216 with a later model 235, the adapter centers the water pump with the radiator. Without it, the water pump sits too low behind the radiator and the top 3 inches of the radiator - the hottest part - gets no fan assisted air flow.

1950 Chevrolet 3100 (Ol' Roy)

1939 Packard Standard Eight Coupe (The Phantom) | 1956 Cadillac Coupe de Ville (The Bismarck) | 1964 Ford Galaxie 500 coupe |1966 Ford Mustang (Little Red) | 1969 Pontiac GTO (The Dishpit) I 1979 Ford F-100 | 1976 Ford F-150 (Big Red) | 1995 Ford F-150 (Newt)