Thanks for your reply. I am a newbie with afni, so pardon my ignorance.
I would like to avoid aligning stats and anat as it adds another step of interpolation. Is it possible to concatenate the warp from epi->anat->tlrc and then apply it directly to stats+orig?
I had tried to compute and concatenate the transformation matrices (epi->anat->tlrc) and then use 3dAllineate on stats+orig but then the q values from FDR curves were not working in afni gui.