1970 Duster project in Sweden
OEM brass radiator or thicker aluminum one? If it's a thicker aluminum one, then use a fan clutch from a 1990 jaguar XJ6 it fits and is a fair bit shorter. It should come with a centering bushing for the mopar pump shaft, and is SAE thread. With that I used an 18" 6 bladed fan made for a clutch. I got it from summit. I think it's made by flexalite.