Yes, ^^^^ he did. LOL
Anyway.....on factory 16's wheels, you can run up to a 255 width tire. 265's won't mount without touching. And that is just plain retarded and make me want to throw rotten tomatoes at people. 255's are bastards and hard to find and the set I had wore like crap. Never again.
Spacers. The thing about spacers is that you can't run 1/2 or 3/4 or 1". Not sure about the 3rd gen trucks, but on the 2nd gens, the minimum you can run is 1-3/4" as stated above. The spacer has to be at least as long as the end of the stud bolt from the face of the hub unless you are going to drill an entire new set of lug holes in your wheels for clearance. Spacers are a PITA. I loved those 285 tires and they were awesome of the pavement. It just sucks removing 48 lug nuts to rotate tires.
You want some clearance between your tires. If they rub, or touch when loaded, they create heat. You will pick up a rock between them and it will wear a hole in the sidewall. I run factory rims and size on this new truck but I do have a 3/8 plate spacer between them. It leaves just enough lug thread to come to the outside of the nut and it gives me just that much more room for mud/rocks/crud to clean out. 3/8 is the maximum spacer you can run without offsetting and being required to add an entire new set of lug nuts.
$.02