1997 dodge cummins 2500 4x4

does anyone know what the clutch fan nut is? standard or reverse?

as you are standing in front of the truck facing the fan use an 1 7/16 wrench and slide a screwdriver between the pulley screws to keep the pulley from turning, turn your wrench clockwise (as if you were tighting a normal nut) and your clutch fan should come loose. good luck yes, I answered my own @%$# ?

I'm ting t9 take the cluch fan off and put a mechanical fan on and all I need to know is what the threading in the pump is

What pump? And why would you want to get rid of the clutch?