Bunsen, so you know, my Ultra 320 74GB SCSI Drives use an adapter to go to 68-pin from 80-pin SCA. The adapter has a jumper you can set it into SE as well as TE options. I don't know of any Ultra 160 SCA-80 drives out there, do you?

I might be wrong, however I do know my ultra320 hitachi drives do indeed do SE. I have tested it with a Power Mac 7200 and they worked. So there is a way to at least set SCA-80. Maybe it depends on the adapter. I haven't found any Ultra-320 68-pin drives out there. It seems the 320 were meant for SCA systems.