I have 285/75/16 as well on my stock 2000 XLT 4x4.
The 4x4s do come with the stock 1" body lift, too, from what I understand.
FYI, 285/75/16 = 33" and 315/75/16 = 35" APPROXIMATELY
So, it is a decently taller/wider tire.
Once you are looking at 35"s and up, you might be wanting to regear...