The heads do stick out on both sides... but that isn't unlike most airplanes with glow engines or Zenoah carbs & mufflers on many 50cc warbirds....

The only thing that I am trying to figure out is the thickness of the prop hub w/the spinner.... the lock bolt has no threads ( the prop/spinner backplate) takes up all the room..
Any suggestions???
Avalanche are ahead AGAIN 3-4 with 3 Min left to play.... had to turn off the Game, as I would be upset if the MN Wild can't win it...