GT 3.2 V6 front sway bar bushes.

[oz3litre]

I think my GT needs new anti sway bar bushes on the front. There has always been an annoying clonk on the passenger's side when hitting potholes. The other side seems fine. Everything else, such as the control arms etc, was checked by my mechanic recently and there are no problems with those. He wasn't able to check the sway bar bushes because he only has two post lifts and couldn't check it with the weight on the wheels. I have a few questions:

1. Are the bushes on the V6 23mm?
2. Has anyone tried the Powerflex bushes? I can't get original ones separately locally.
3. What is involved in replacing them? I believe the originals were sold with a new bar and to replace just the bushes the brackets have to be split and re-welded.

Any help is greatly appreciated.