  We consider $Z'$s in heterotic string derived models and study $Z'$ resonant
production at the TeV scale at the Large Hadron Collider (LHC). We use various
kinematic differential distributions for the Drell-Yan process at NNLO in QCD
to explore the parameter space of such models and investigate $Z'$ couplings.
In particular, we study the impact of $Z$-$Z'$ kinetic-mixing interactions on
forward-backward asymmetry ($A_{FB}$) and other distributions at the LHC.
