Differences between the dual-engine Centaur stages of the Atlas IIIB and V

[Vahe231991]

I know that the Atlas V largely differs from previous Atlas SLV variants in having a new first-stage structure despite retaining the Centaur upper stage, but I found out that the Atlas V N22 exclusively used to carry the Starliner manned spacecraft has a dual-engine Centaur stage, similar to that of the Atlas IIIB. How does the dual-engine Centaur upper stage of the Atlas V N22 differ from that of the Atlas IIIB?

[Jim]

Newer avionics and different helium and hydrazine tank layouts.