all six injectors dead

I have a OBD1 4.0 that is a swap candidate. I took the injectors in for cleaning and was told all six are blown. I want to use the wiring, ECU and PDC that came with the 4.0 but I don't want to burn up a new set of injectors. Is it possible to bench test the system (maybe with a multimeter) before installing injectors?

Yes, mostly.

You can test the harness for continuity or shorts, you would want a short finder with a transceiver/receiver set for that. You can test for a proper 12 volt supply. Not sure how you might test the ground signal for firing the injectors from the PCM/ECU other than hooking everything up, except for the injectors, and then using one or more NOID lights are a high-end meter like a Fluke to test for the ground impulse to the injector connectors.