Okay, this would mean a lot of work... but I would love to see the Rocker Arms actually working on those big inline Engines :-)
There would be no need to research the correct Firing Order - no one will be able to verify that, once, the Engine is running... even @ idle.
There is always this Feeling, that the Engine isn't really "alive", when you are flying around and see the Valvetrain standing still like on a Photo...