BM Naruto would wax current Sasuke, don't be silly.
SM Naruto was stated to be stronger than MS Sasuke and he has to the feats to back it up. Sasuke's fledgling Susanoo would have been virtually useless since Naruto could break it with his bare hands or use his FRS.
KCM Naruto is also comfortably stronger than EMS Sasuke, he has an outrageous speed advantage and even clones have taken out Kage-level shinobi with relatively little difficulty. Sasuke would get beaten fairly comfortably then.
BM Naruto is on a whole other level and current Sasuke would lose, let alone EMS Sasuke whose greatest achievement was a full-bodied Susanoo. The Gokage, not to make light of them, were taking on five of those for an extended period of time. Naruto would wipe him out so quick Sasuke wouldn't even see it coming.
Given the enormous power boost Sage Mode gave to Naruto back in the Pain arc, one could imagine the true difference between BM and BSM. BSM would wipe out current Sasuke with little difficulty.
In all forms Naruto has the strength and speed advantage. He has better jutsu and a fighting style that simply trumps' Sasuke who won't be able to keep up for long, let alone actually compete. In a version of the manga where they went all out with no plot limitations, you'd be a fool to think Sasuke stands much of a chance against Naruto.