285/65's on 18x9's?

[silverad03]

I'm working towards putting some new shoes (tires & wheels) on the truck next year and I'm thinking about the EA 178's. The truck in question is a 2003 1500 Silverado Z71. I have put the ford keys on the torsion bars to level it out.

 

The EA 178's only come in size 18x9 with 5" backspacing and +2mm offset and I'm thinking about putting the BFG A/T KO's on those wheels in size 285/65/18.

 

I'm not sure what the factory wheel backspacing is, etc. Anybody have an idea how much tire is going to stick out (w/o any fender flares)? What kind of rubbing issues am I going to have with this setup? I'm prepared to trim the front bumper valance a little bit. Also, would I be able to maybe jump up to a 305 or a 315 without significant trimming?

 

 

-Jason