With a big block in an A body, I would put the biggest baddest radiator that will fit money can buy. Up to and including notching the frame rails for a wider core. Also, on the fan. If you don't have "something" that can move in the neighborhood of 4000 (that's FOUR THOUSAND) CFM, you "probably" ain't gonna get the job done. AND look at how new cars are made. Grilles get smaller and smaller as frontal areas decrease for less wind resistance. SO, that means diverting more air THROUGH the radiator instead of around or under it. Look how new cars have all "that area" on the under side between the bumper and the engine cradle closed off with plastic shields. They aren't just there to make things "look neat". They are part of a system to help redirect air into the radiator. The other part to the system is an air dam "of some kind" under and just behind the front bumper. This pushes air forward and up, so that it is then sucked into the grille and through the radiator. All of these things together will cool even the hottest of builds.
