We have performed large-scale shell model calculations of the Gamow-Teller strength distributions in N ? Z pf -shell nuclei. These calculations were motivated by the experimental attempts to measure the low-lying GT strength for the even-even N = Z + 2 or N = Z - 2 nuclei 46Ti , 50Cr , 54Fe and 62Ge , where a sizable low-energy GT strength could be interpreted as reminiscence of SU(4) symmetry; in the limit of exact SU(4) symmetry the GT- strength would be concentrated in a single transition to the lowest T = 0, J = 1+ state in the daughter. We confirm that the SU(4) symmetry is strongly broken by the spin-orbit interaction and by increasing neutron excess.