This will be silly to many, but I think it's still a worthy question (yet another facet to my weirdness):
Say they make a time machine (don't give up yet... this is on-topic), and you can buy your 7.3L Superduty brand new, with the factory warranty that is valid from today. Just for leveling the playing field, you would have a modern sound system, backup cam, and GPS.
The other option is a 6.7L with the same trim... but of course, the 6.7L is quieter and has more bells and whistles and better suspension.
There is no difference in price between the two trucks, because the time machine round-trip (with an 8000-pound truck) is pretty expensive.
What do you buy?