Naruto would initially lose. He is childish, still chasing rainbows when Sasuke has obviously grown up... Sasuke has not and will not hesitate to kill Naruto... If he doesnt change his resolve, Sasuke will eat him up and sh!t him out. Im sure you can all agree, because at this point... Sasuke can match Naruto Bijuu mode vs EMS. So you cant say Naruto is stronger... We have yet to see what his EMS can do, who knows? Maybe there's a perfect Sasano'o up his sleave. He has so many variations of techniques when im sure Sasuke knows Naruto spams Rasengan. Naruto can counter Sasuke's genjutsu due to Kurama. He can dodge his Amaterasu... And yes -__- Naruto can dodge his Kirin also

so this would either be the best match up or the worst cause they each have counters for each other... Naruto's wind element cancels out his lightening, whereas Sasuke's fire eats and digests Naruto's wind.
Naruto will need to undergo a dramatic change in attitude before this fight if it ever takes place... I'd hate to see the main character die because of a stupid one-sided childhood friendship.