They would be OP. They would even get up to the 8th Gate and if they work as a team Naruto might perform the EE while Sasuke goes 7th Gate and does Hirudora with his PS and Sakura using regular Taijutsu moves.
Sakura survives the eighth gate, Naruto's power increases on a waaay larger scale considering
without Kurama's assistance he sent Sasuke flying into a wall leaving a dent and his speed increases,
Sasuke's speed increases to his advantage.
I thought of this, but they would be too strong for plot. They are already the strongest without them.
Naruto and Sasuke with their Sage powers are already gods. Sakura would be the biggest benefactor since the super speed combined with her super strength would be hax, and her byakugou would reverse any toll her body takes from higher gates.
Naruto in KM + 8 gates?
That would've been op becuase Kurama healing powers are op...
He'll get healed!!!
So he'll be able to fight all time in 7 gates.