92 gm alternator

Should I be able to disconnect the battery and not kill the engine? parts store guy said the newer cars with all the electronics will die, but I would think that it should still run with good alternator. does anyone know?

It is not a good practice to do. But it will stay running. You take a chance of spiking voltage to the PCM and blowing that. So, as I said, it is not a good practice and I do not condone it.