Ok, I'll take my time on this one and explain something.
Why naruto will or can't be more powerful than sasuke (not because I'm a fan, u'll see) :
1: the story is based on the fact that naruto and sasuke are rivals and that naruto want to bring him back. Considering that situation, when sasuke will get back, kishi will inevitable end the manga. It would really suck to push the manga too far onl for money.
2: Considering the num 1, trough out the manga, sasuke (even if not the strongest) was given little boost to always seem stronger than naruto (not always, but when they faught seriously).
3:Now considering num 2, a new fight between those 2 (naru vs sasu) is innevitable, considering that sasuke is heading toward konoha. This can only mean 2 things: either sasuke during his trip in direction of konoha learn some new awesome jutsu and got,once again, boost up. Or naruto will kill sasuke in this battle, signing the end of the manga. That last option is unthinkable, considering how much left there is in this story, ninja war, akatsuki, kage summit...
4:I know some of u dislike the idea that sasuke will die at the end, but think about it. Think like sasuke, all his life he has given himself to his emotion of revenge, jealousy and hate. Even if someone come to sasuke and tell him an abominable truth about madara or someone else and deviate his anger toward konoha into an other objective, sasuke will never accept konoha help. He has been representing the antagonism of naruto form the beginning,one of them has to die at the end.
If u have any comment or correction in relation to my tread, please tell me, and I will gladly make the correction. Rep is also appreciated!