Fan clutch on a big block?

Is anybody on here running a fan clutch on a big block? From my research on here it appears the Hayden 2765 wont fit my 383 Duster as I measure about 2 3/4 inches from the water pump flange to the radiator, the same dimension as the Hayden clutch leaving me no room. I really don't want to go electric and am tired of the my Duster sounding like a B-52.