My z71 has rust on the lower panel behind the front door and on the back fenders.  Like most other GMC's and Chevys this was bound to happen.  How far will the rust travel up the body?  Will it stop after it gets to a certain point? 

Thanks

CJW1500

rust will just keep on rusting, it won't stop, If you want a quick, non-guarranteed fixed buy some rust converter from wal-mart or something and spray it on or use a brush to brush it on. but like i said i have heard mixed opinions on this to where it does and doesn't work. Best of luck.  

You can cover rust up with expensive fancy paints but it will eventually win.  If the rust is not attacking your body mounts and you don't mind a rusty rig just leave it alone.  If you want a nice looking rig you will have to cut it all out and put in new metal or find a rust free cab.

sand it up a little bit and paint it with some outside paint put a few layers on it should stop it or at least slow it down