My 17 in clutch fan is in a similar position as yours, about a 1/2 inch over the top of the core (cold case radiator). My fan is about 1/2 inch from the radiator. Mine is a 360. The fan fits nicely in the shroud. Make sure the fan is about 1/2 in, 1/2 out of the shroud. I learned that the hard way.
