Small Block in an early A - how much room for a fan?

Professor Fate said
At one time, @slantsixdan had mentioned a Mercedes unit that was even shorter than the Hayden, but I forget the exact application.

Good call. I have this info somewhere, and I have one of these fans squirreled away in Parts Mountain.

Thanks to all for the good info. I will file this for use when I get closer to putting this together.