Rotating Kit Assembly, 2.77 in³, Model 70423

For a Model 70423 piston pump, yes, this is the correct rotating kit assembly. It carries the 2.77 in³ displacement spec that matches that pump family and is sold under the Eaton Char-Lynn / Danfoss Power Solutions line specifically as an accessory for those units. The catalog number on this one is C1KD43, supplier part 70423-617, so cross those against what you have on hand before ordering.