73 340 duster exhaust tips weleded or not?

I would tack them in place or they could fly off when your not looking. Many have gone missing due to the clamp not being able to hold the pipe onto the steel tip. It doesn't crimp like the rest of the pipes.
I agree that this may happen on some pipes/mufflers OMM. It is important to note that most any of the pipes where the clamp pinches them have a couple of slots in the pipe (and mufflers do too, see photo) so it/they can be clamped tightly without crushing the pipe. Hack saw two 3/4" long slots in the pipe and you are good forever.

voefinalactendDSCN0121 copy.jpeg