Yeah, if this is normal 185 setup you have a lot more than just hook up the ecu. Do you have a link that verifies a stealth ecu is a 205 ecu? And by stealth, do you mean dodge stealth?
For the 205 ecu to even work, you need to repin the harness at the ecu. Depending on your year and model, you will need to look up ecu pin outs, then move around the proper pins. Next, you need to convert to MAP sensor. and there is more to do in the engine bay. You will have to do a search for the thread here on the conversion for the ecu.
Good luck.