Matt93SE said:Basically what he said.
Just make sure you get the same trim model so you match up the engines.
your variations: (also note there are fed spec and cali spec chips for each of these)
89 VG30E auto
89 VG30E Manual
90-94 VG30E auto
90-91 VG30E manual
92-94 auto VE30DE
92-94 manual VE30DE
source: Jim Wolf Technology's ECU page. These are all the aftermarket ECUs. I've talked with a tech there and as long as they use the same aftermarket ECU, then the stock ones will interchange. (you can use a 90 VG auto ecu on a 94 VG auto ecu)