Champion radiator - I cut her open

Can you run a clutch fan?
I am using an 18" 6 blade flexalite clutch fan about $38 from summit, and a fan clutch from a 1990 shaguar XJ-6 from rockauto for about $35. It comes with a centering bushing for the mopar water pump snout, and the bolt thread is SAE its 3/4" shorter than a stock mopar fan clutch to clear the thicker aluminum radiator. This is on a small block. Not sure how much room you have w a 383 compared to a small block. Oh and be sure to run a fan shroud, and the rubber flap on the under side of the hood that closes agains the radiator support. Ram air will always choose path of least resistance.

I have a thread in heating and cooling on here called "fan shroud questions" do a search. It details how i made my own fiberglass shroud to go with a ECP aluminum radiator and my 18" clutch fan.

Hope this helps
Matt