Models with gauge symmetry SU(3)_c X SU(3)_L X U(1)_x, also called 3-3-1 models, arise as an interesting alternative that explains some of the fundamental problems of the Standard Model (SM). For example, introducing a family non-universal U(1) symmetry, the 3-3-1 models can account for the family replication problem and may generate a hierarchical difference between the heaviest quark family and the two lighter. These models introduce new types of heavy particles, which may be searched at Hadron Colliders, providing additional information on the nature of the extended gauge structure beyond the SM. In particular, these models extend the scalar sector of the SM into three SU(3)_L scalar triplets. In the version without exotic charges, after the spontaneous breaking of the gauge symmetry, the model contains 4 massive charged Higgs (H_1^±,H_2^±), one neutral CP odd Higgs (A^0), 3 neutral CP even Higgs (h^0,H^0,H_2^0), and one complex neutral Higgs (H_3^0). In particular, several production and decay channels of the lightest charged Higgs bosons H_1^± at LHC have been calculated in the literatura. In this work, we study the Drell-Yan pair production cross section of the heaviest charged Higgs bosons (H_2^±), including the contribution of a new Z’ neutral boson associated to the SU(3)_L gauge sector.