This is a fight that could srsly never end. Seriously-- are these guys even capable of hurting each other...?
The series has built into both characters a whole lot more defense than offense it just doesn't seem like they can actually do anything to each other.
Naruto Offense v. Sasuke defense
First off, Sasuke has the Rinengan, so he is able to cancel any Ninjutsu-- so rule out basically every kind of huge ninjutsu as long as Sasuke doesn't overuse his Rinnengan. Sasuke is different from Pain in that he can absorb nature energy.
On the Taijutsu front, Sasuke is physically slower than beast mode Naruto, but the predictive powers of his Sharingan + the Rinnengan's teleportation ability that trumps Naruto's physical speed basically makes Sasuke impossible to hit with an attack that doesn't cover his whole teleport range (and again, Sasuke can just absorb big ninjutsu). Naruto could try fill up that whole space with shadow clones. That's a potential weakness, but not one likely to come into play because--
Susanou. If everything else fails (which it won't) Sasuke still has Susanou, which let's Sasuke fly (moving his teleport zone) and protects him from most attacks.
Sasuke offense v. Naruto defense
Naruto is physically faster than Sasuke (by a LOT-- Sasuke was overwhelmed by Raikage's Speed and hasn't gained any major physical boosts since, where Naruto was faster than Raikage's just with his incomplete ninetales form-- now he has connection to ALL the tailed beasts' Chakra, and can combine it with his natural sage chakra too). Speaking of sage mode, 6th path sage mode's sensory ability combined with Naruto's superior speed and ability to Fly is going to make it all but impossible for Sasuke to hit Naruto with anything-- even with Teleporting. All of this presumes Sasuke actually figures out which body is the real body and not a Shadow Clone, pretty much impossible since Kaguya couldn't do it even with ALL THREE of the great doujutsu (while Sasuke lacks the Byakugan).
Naruto also has the tailed beasts inside him, making him immune to most Genjutsu... so yeah. It's a potential weakness, but not one likely to come into play.
Finally when all else fails (which it won't) there's still Naruto's beast shrowd and regenerating abilities to take into account-- and his sage healing powers. On top of all this, Naruto is able to use the 6th paths black matter like Madara, which is capable of making basically indestructible shields, so in the unlikely event Sasuke actually hits Naruto with something, there's not a whole lot that something can do in terms of lasting damage.
In fact all of these types of problems existed in the fight with Kaguya, who could only hurt Naruto/Sasuke with her spears, because those were the only attacks she had that could trump Naruto's healing/shields and Sasuke's Susanou/jutsu absorption.
Sasuke and Naruto too had nothing to actually hurt Kaguya, and only got around her defense by sealing her (as opposed to beating her by damage).
In Sasuke v Naruto, there will be no sealing. There are no attacks either has as decisive as Kaguya's spears (which were still pretty crap in practical application).
Unless Kishi totally ignores the canon powers of both characters (which he probably will, cause otherwise it'd never end), this might as well be a double-slapping contest between two Blissey.