  As described previously, a new massive gauge boson (X) coupling only to the
third family produces a tantalizing pattern of deviations away from the
standard model. These include increasing Gamma_b/Gamma_h and decreasing the
alpha_s(M_Z) extracted from Gamma_h/Gamma_ell . We review the status of these
X-Z mixing effects. We then calculate X boson induced vertex corrections to Z
partial decay widths and to ttbar production in ppbar colliders.
