I don't know much about this stuff, but I made one that was polished.
It looked like this:
Willys drag car.jpg
For this car:
Willys, 3_4 front, copy.jpg
It was a blown Mopar, with solid mounts - so I could hold .250" on fan clearance. It was a record car back in the day, but now the blower just works at street levels, so the fan has to cool pretty well.