Don't honestly know if there are any fan blades of smaller size that would fit that Dodge assembly. Since that fan blade is metal, you could conceivably remove some material from each blade. Would just need to mark it carefully so as to keep it in balance. You'd be taking 1" off each tip to get down to 20" Don't think that would have any adverse effect on its cooling ability. Here's what the fan blade looks like.
329.4 KB Views: 36