  We apply a recently developed dilaton-pion effective field theory for
asymptotically free gauge theories near the conformal window to the $SU(3)$
gauge theory with $N_f=8$ fermions in the fundamental representation. Numerical
data for this theory suggest the existence of a large-mass regime, where the
fermion mass is not small but nevertheless the effective theory is applicable
because of the parametric proximity of the conformal window. In this regime, we
find that the mass dependence of hadronic quantities is similar to that of a a
mass-deformed conformal theory, so that distinguishing infrared conformality
from confinement requires the study of subleading effects.
