  We examine the prospects for probing heavy top quark-antiquark (t-tbar)
resonances at the upgraded LHC in pp collisions at $\root_s = 14 TeV. Heavy
t-tbar resonances (Z' bosons) are predicted by several theories that go beyond
the standard model. We consider scenarios in which each top quark decays
leptonically, either to an electron or a muon, and the data sets correspond to
integrated luminosities of \int L dt = 300 /fb and \int L dt = 3000 /fb. We
present the expected 5-sigma discovery potential for a Z' resonance as well as
the expected upper limits at 95% C.L. on the Z' production cross section and
mass in the absence of a discovery.
