When I had a 440 in my Duster, I used a Howe 19x28 radiator, with a pair of Perma-Cool 14" fans. 13" fans would have fit better. This pic was taken before I built a shroud, which I highly recommend. Even when I swapped to a blown 528 Hemi, I never had any cooling problems. I think I paid $200 for the rad at Summit.

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Gone to the dark side with an LS3 powered '57 Chevy 210