I always had a soft spot for the early 40's thru 48 Cadillac flathead V8. They had their exhaust ports sandwiched next to the intake ports on top of the engine (in the valley between the heads). I always thought some enterprising sole could do a "bunch of snakes" set of headers that would freak out most younger gear heads.
Too bad these engines are so damned heavy,,,,,,,,,,,,,,
No pictures available to post, but you get the idea.