Merc factory aftermarket open exhaust. Had an actual factory part number.
Printable View
we had 3 sets of them in Miami..Open stacks that is. were easy to get.
...Elmer Carl Kiekhaefer...
https://assets.hemmings.com/story_im...00-0.jpg?rev=2
Those old D-7s were something :)
...Fred Kiekhaefer...
http://www.mercuryracing.com/wp-cont...d-with-565.jpg
...1959 45 H.P. Kiekhafer Mercury...
http://www.marineengine.com/boat-for...0&d=1274617338