Stepped surfaces of face-centered-cubic crystals are naturally chiral if the step edges include asymmetric steps. These surfaces can, in principle, exhibit enantiospecific adsorption properties if chiral molecules adsorb on them. To provide theoretical characterizations of these enantiospecific properties, we have used Monte Carlo simulations to examine adsorption of two chiral hydrocarbons, trans-1,2-dimethyl-cyclopropane and trans-1,2-dimethyl-cyclobutane, on Pt(643) and Cu(921), two naturally chiral surfaces. These simulations are the first to include the effects of intramolecular relaxations. We also present a simple procedure for predicting the low pressure enantioselectivity of adsorption from a racemic gas phase mixture based on simulations of individual enantiomers.