Naruto is on par with Hashirama, but I don't think he would be able to beat him. At best, they both die in the struggle.
While Naruto has Sage Chakra that he can add to Bijuu Mode, Hashirama has Sage Chakra that he can add to the Wooden Dragon. Naruto was already bound by it once and lost a TON of Kurama's chakra.
I also feel that if Madara wasn't able to fully protect Kurama with Susano'o against Shinsuusenju, Naruto wouldn't be able to do much against it. Unlike Madara though, Naruto would probably not just charge straight into it knowing that he doesn't really have a defense like Madara did. So he may come up with an alternative.
Like I said though, Naruto would give Hashirama difficulties, but I don't think Naruto could pull it off. Although I used to a while back.
Naruto has also only shown Bijuu Rasenshuriken with his Rikudo Mode. He never showed this in BSM. We cannot give Naruto abilities we did not see him do in a previous state because he never showed them in that state.