maybe the reason naruto looks like the fourth hokage has nothing to do with them being related by blood.

when the third hokage uses the soul binding technigue or Oro he said that both souls would be locked together fighting for all eternity. perhaps when the fourth sealed the kyubi's spirit within the baby he also sealed his own. this might have affected the baby's appearance.

note - naruto has whisker thingies, presumably because of the kyubi, showing that this sort of binding does alter appearance.

what do you think?