  We use simple current techniques and their relation to orbifolds with
discrete torsion for studying the (0,2) CFT/geometry duality with non-rational
internal N=2 SCFTs. Explicit formulas for the charged spectra of heterotic
SO(10) GUT models are computed in terms of their extended Poincar\'{e}
polynomials and the complementary Poincar\'{e} polynomial which can be computed
in terms of the elliptic genera. While non-BPS states contribute to the charged
spectrum, their contributions can be determined also for non-rational cases.
For model building, with generalizations to SU(5) and SM gauge groups, one can
take advantage of the large class of Landau-Ginzburg orbifold examples.
