Go for it....
No, there shouldn't be any problem, as long as they match up. You'll want to be careful not to over torque.
I've never heard of somone just breaking their venturi or steering nozzle. Are you rough housing it? If so, you may look at your riding habits. Because if your breaking the weakest link and you strengthen it by switching to aluminum, then your pump housing becomes the weakest link. Do you know how much it will cost to replace the housing?.......