Results for the spectrum and the F and D parameters are obtained with precision similar to that in the quenched approximation. Present data for m q ≥ m s show measurable effects due to vacuum polarization only in the pion-Nucleon Σ term suggesting that Σ sea ∼ Σ val . The lattice update is being done on the Connection Machine which is very well suited to simulate QCD with 2 flavors of Wilson fermions (with mass close to the strange quark) using HMCA on 16 3 × 32 lattices.