In theory, although you are the first person to ask for it. Again, you would have to change clutch and brake lines, throttle cables. On top of that you would need to have the switchcube wires extended, brake and clutch switch wires extended and new handlebar clamps and bolts. Also the bar end weights are different on a california.
Since we have only ever done the California in Euro 4, we wouldn't have the correct length brake hoses if the bike for conversion wasn't euro 4.