Fan clutch options

so the longer shaft unit put the fan so close to the stock radiator in my 1970 Dart that I had to take the radiator out to get the fan and water pump off - no its not supposed to be that way. This was true for both the old unit that Hayden sold for the application and the MP unit that came with a fan. I have 2 original fan clutches from 1970 Darts with AC and the heavy duty radiator and the Hayden 2947 is the closest to the original from the mount surface where it mates with the water pump to the face of the unit. I have them on two small block Darts with no cooling issues.

Remember that the fan clutch has to fit on the water pump center shaft snugly - if there is slop you can't precisely get the fan centered leading to an off balance clutch and fan that will quickly eat the water pump bearing and seal.