What suspension setup has been absolutely proven to stop feathering and improve tire wear.

 

If good tire wear is all you care about then get camber arms for the front and rear and get rid of the Shitenzas. Set your camber to 0 degrees on all 4 corners and tire wear will greatly improve. That is the only way. If you do any kind of lowering you are just going to add more negative camber and wear the tires even more. If you decide to go this route, you can kiss a good deal of your handling good bye though.

 

whats a good camber kit to get and how much does it cost

 

Check out this link:

https://my350z.com/forum/showthread....hreadid=108270

There are a few more such as Stillen and prices can get quite expensive.