David Megginson wrote:

Perhaps it's because the O-320 (and O-360?) is able to
have all four cylinders equidistant from the carb.

Doubt it. The carb on *my* O-320 is located behind the engine. No way all four
cylinders are equidistant from the carb. I doubt that Lycoming has set up a
tuned induction system either, but it's possible.

George Patterson
You can dress a hog in a tuxedo, but he still wants to roll in the mud.