by Kent Williams (CAT)
Ford makes a 6-bladed metal fan that is the same diameter as the stock 4-bladed unit. That fan is PN C9DZ-8600-A. The bolt pattern and hole size are correct, but the center hole must be drilled out to 1″ diameter.
Before installing, spin the fan to see that it clears the rack housing. I had to remove a small amount from each blade by grinding. Check balance carefully. I have used this blade for several years and have had no overheating at idle or low speeds here in the Texas heat.
Editors note: Only the rear corner that interferes with the rack needs to be removed, not the whole blade length.