Watch out for this, serpentine belt V8's spin the fan in the opposite direction to pre-serpentine and diesels. Therefore the thread is normal and more importantly the fan blades are pitched the opposite direction.
I had a real problem with an overheating 3.9 until I found that someone had replaced the fan with a pre-serpentine/diesel one so the fan was blowing out instead of sucking air in through the rad.
BTW the rangie has run for a year now with no fan, depending on the aircon electric fans when it gets hot with no overheating problems since.