I want to calculate a groupwise statistical map from individual subjects, which requires transformation into tlrc space. However, since I want to run alphasim on the resultant group map, its voxels need to retain the original EPIRT-obtained dimensions for the adjusted clustering threshold to have meaning.

adwarp does not seem to let you specify individual voxel dimensions, only the size of cubical voxels.

@auto_tlrc is described in -help (usage 1) as being intended to transform an ANATOMICAL dataset

What command-line program could I use to warp out each subject's statistical map into trlc space while still retaining the clunky dimensions of the EPI voxels (in my case 3.75 X 3.75 X 4.8)?

Would I be better off warping every subject with adwarp -dxyz 2.0, merging brains, and then resampling the resultant group map with 3dfractionize?
Jim B