In the framework of the projected shell model, we investigate the competition between the two-quasineutron and two-quasiproton Kπ=6+ states in the ytterbium isotopes and N = 104 isotones adjacent to 174Yb. The 174Yb results are compared with the experimental data. The Kπ=6+ isomer observed in 174Yb is assigned as an admixture of the ν7/2−[514]⊗ν5/2−[512] and π7/2+[404]⊗π5/2+[402] intrinsic structure, which explains the experimental |gK − gR| value. Similar mixing would appear in 172Yb, 176Hf, and 178W. The low-lying Kπ=6+ states are also predicted in 170-178Yb.