Yamato no Orochi is a big ass target, and wouldn't be smart of Orochimaru to use against Kakuzu. A multiple elemental assault more than likely be the end of it. And from my recollection, the things has no actually feats.
Other than that... I mean I never understood what Orochimaru exactly had that threatened Kakuzu outside of summons. All of his snake-based ninjutsu get charred through Zukkoku. If they were to clash in CQC, Kakuzu's V2 version (with the tentacles protruding, and being able to extend extremely far) would suffice to keep Orochimaru at bay.
Honestly, I'm confused on how Orochimaru beats Kakuzu.