You will find a little problem if your files are indeed named i*.1 to i*.392. The wildcard i* will give you files in the order like so

i.1 i.10 i.100 i.101 ... i.109 i.1 i.110 ...

which is probably not what you want. It would be better if they were named i.001, i.002, ... i.382. However, if this is impracticable, then you could use the triple of wildcards

i*.? i*.?? i*.???

which will work correctly. To ensure that this is true, you could use the 'echo' command, as in

echo to3d -time:zt 7 55 1000 -abuc i*.? i*.?? i*.???

which will simply echo the expanded command to the screen, and then you can inspect it.

Please note that wildcard expansion is done by the shell before to3d even starts. This is not a feature of the AFNI package but a feature of Unix.