Before he learned Rasengan? His only means of dealing damage was throwing punches and kicks at a fucker or channeling (his considerable stores of) magic into paper to make it explode.
0 Tail Naruto can physically overpower Orochimaru's massive Snake that does the kind of shit found
here. Base Naruto can survive physical strikes from both in the
Forest of Death and during the
Search for Tsunade. Base Naruto by
his fight with Gaara has caught up to and passed the power he had in the Forest of Death (note, the clones he summoned that Sasuke thinks about as an example of his power were summoned long before using Kyuubi's chakra to summon Gamabunta [his other example].
Worth further note is roughly 3 clones were able to restrain Gaara's arm (note both the clones and Gaara's arm are shaking, as if both are straining to resist movement and move) after Naruto chucked them at Gaara as some kind of diversionary body slam
The beating he took from the army of clones (post
Will of Fire bullshit) was enough to convince Gaara he was fucked unless he went full Giant Shukaku (while he
wasn't recovered from
the explosive tag detonating beneath his tail, he does note he's still able to at least defend himself with his sand... which ends up doing fuck all anyway, hence his desperation)
Also, anyone have a fucking clue what happened to the Snake after it broke his leg in the Search for Tsunade Arc?
Next we see Naruto is he's unconscious with Tsunade looking on in Horror and the Snake seemingly vanished into thin air. Did he defeat it off panel?
Kabuto implies he fought it when he notes Naruto broke his leg in the first place *shrugs*
Kishi has an awful memory as far as I can tell, but its inexcusable to assume he forgot the damn thing in the same chapter he introduced it to the fight
EDIT - More shit from long ago
Neji still
seems to consider 0 Tail Blue Eyes Naruto the strongest fellow he's fought even after downing Curse Mark II Kidomaru (he calls him only the strongest "enemy" he's fought. How he describes Kidomaru is rather a more specific sub-category while 0 Tail Blue Eyes Naruto's is more broad and thus takes precedence and removes any claim of contradiction. While you could point out to how he was non-specific
in an earlier scan here making the claim, the latter one supersedes it as it further clarifies and contextualizes his thoughts).
So you can certainly make the argument for it past a certain threshold *shrugs*
Would mean 0 Tail Blue Eyes Naruto scales to Choji's feats vs Jirobo I guess given he's the
defacto weakest of the Sound 4