I'm not sure why these arms could not be done. Teflon is widely known for it's temperature resistance. It has an workable operating temp of -400 deg F to 500 deg F.
(go to http://www.mcmaster.com/ & type in teflon).
According to this site
http://www.lenntech.com/teflon.htm
the melting point of Teflon is 327 deg C (620 deg F). Dupont, the makers of Teflon claim their the lowest melting point more any type of Teflon is 500 deg F.
http://www2.dupont.com/Teflon_Industrial/e...fo_compare.html
Powder coated parts are cured at 375-400 deg F. If parts are being ruined, I wonder if it is actually Teflon inside the ball joints and not some other cheap plastic. I would also be curious of the grease inside the joint. What about the rubber the ball joint boot is made from? What type of rubber is this?
Just like nitro above, I'm not trying to be a smart ass. I really want to have my a-arms done as well & so far don't see a huge reason as to why not. But people on here have got their arms ruined by this & the reason doesn't seem totally clear.