83Stang5.0

Just because 2 ecu's are meant for the same size injectors, doesn't mean each will run the opposite's engine. Tip in, throttle body adjustment, environmental conditions(humidity,altitude, air temps) all play a huge role. Each being slightly off, can cause a complete no start and no run. It's pointless to argue what it "should" or "might" do, because it's still not what it's meant to do.