Whats the difference between 4x4 and z71? I just bought a 2005 canyon sle, 4x4, crew cab, 5cyl. It does not say z71 on it anywhere. Im just wondering what the difference is. Also I am looking at putting a lift on it and am wondering what the best suspension lift would be. I also want to put 20" rims on it and am wondering what is the biggest size tire with these rims that i could use.