The pattern for the second dataset would not be altplus/alt+z. You can feed the pattern to
3dTshift with @filename.
Also we recommend against using the "-Fourier" method at this point because it can (among other things) cause excessive ringing with noisy data. I would recommend using the defaults from afni_proc.py (-quintic).
Furthermore, definitely highly recommend using afni_proc for all of your processing needs since it's updated with the newest recommendations, latest and greatest features, and will say nice things to you in HTML that likely make reviewing data easier.
-Peter