Looking at LT285/75/17 Nitto's on 17" fuel hostage wheels-have a choice of 4.5 or 5" backspace-what is preferred.

 

4.5 the wheel will be sitting out further than if ya go 5" , backspacing is measured (you might already know this, I don't know) from back of wheel to mounting surface. Google backspacing and there is a site that has diagrams. Some lifts require to have a 4.5 or less backspace so it clears the rear sway bar bolts among other things. Seems like most like as well as I, go with the 4.5". Really a personal choice.

 

I wasn't sure if I needed to be wheels pushed out further than the 5" to prevent rubbing or if running 5" bs wheels helped with stuff of wheels into fenders.

 

I have Nitto Trail grapplers 295/70R17 on Level 8 Strike 5 wheels, with 4.63" backspacing. No rubbing issues and the tires stick out about 1/2 past the fenders.

 

You will be fine with the 5". I run 315/75R16 Duratracs on 16x8 wheels with 5" of bs. No rubbing, front or rear, at full lock or full flex.

Stock wheels have 6.25" bs, fwiw. So if you account for this when widening your tire, you'll be fine.