IAC should close when you step on the gas pedal..... that shouldn't cause a stall. I would more suspect TPS, Low fuel pressure, or failing crank sensor.

 

If you're sure there are no vacuum leaks, then see what the intake air temp sensor reading is. If it's coated with oil, clean it n see if the temp changes. This caused the "stalling" on my old beast (96 Ram 5.2) a few years back.