You could go to a tire shop and ask for balancing powder. Its used in truck tires. One packet does a truck tire so start with a little and experiment. I personally dont think it works but some guys swear by it.
What special Steve said is right. I love mine and am disappointed I won't be able to run them with my cheetah.
I think they should support 70hp without much fuss.
I even had a yz490 and never noticed this
But,
465/490 parts are hard to find in decent shape if at all it seems. You are dealing with parts that are older than the Banshee shit so its also a crap shoot. After market basket? Good luck!
http://img.photobucket.com/albums/v114/Fraggster/IMG_20120207_155441.jpg
http://img.photobucket.com/albums/v114/Fraggster/IMG_20120207_155423.jpg
No dents. Paint is chipped where shearer didn't clean off the flux after he brazed the stingers on.