The non-Markovian spectral theory presented in the preceding paper is applied to the calculation of the pure rotational spectroscopy of HCl in liquid SF6 and its comparison with available experimental far-infrared and anisotropic S-branch results. A quantitative and qualitative study of memory and interference effects on the overall infrared and anisotropic Raman spectra has been carried out. The relation of these effects to the time scales of the dephasing processes and the strong cancellation effects between interbranch and intrabranch mixing are especially stressed. The statistical parameters required for the theoretical calculation of the profiles have been obtained from a microscopic extended cell model for the liquid.