  We analyse the phenomenological viability of heterotic $Z_3$ orbifold models
with two Wilson lines, which naturally predict three families of matter and
Higgs fields. We study the orbifold parameter space, and discuss the
compatibility of the predicted Yukawa couplings with current experimental data,
thus evaluating the viability of the orbifold configurations. We address the
implications of tree-level flavour changing neutral processes in constraining
the Higgs sector of the model, finding that viable scenarios can be obtained
for a fairly light Higgs spectrum.
