The ground state Q value of the reaction 58Ni(7Li, 8He)57Cu has been measured [Q = -29.564(50) MeV]. The cross section for this reaction was found to be 130(30) nb/sr at 5.0 deg in the laboratory. This is the first report of the use of the (7Li,8He) reaction and the first measurement of the 57Cu mass excess. The deduced 57Cu atomic mass excess is -47.35(5) MeV. The implications of this result with respect to Coulomb displacement energy anomalies and nucleosynthesis of elements with A > 56 by the rp process are discussed.