ive done a bunch of searching and still cant get my head around backspacing.

i have a 2004 heritage F150 scab 2wd with 1.5" leveling kit. right now im using stock 16x7 rims on 265/75/16 tires. im wanting some new wheels, both are 16x8 since i will keep my current tires since i just got them a few months ago. how much will they stick out, one says backspacing is -06 and the other says 10? im so confused by this.

also, if i get one of these wheels, do you think i could run like a 285/75/16 terra grappler with no rub and no more lift?

and hers a pic of my truck if it helps, sorry for quality

 

Those numbers are offset, not backspacing. You want 4.5 inches of backspacing which is the same as your oem wheel. This means a 8 inch wide wheel with 4.5 inches of bs will stick out an inch farther than your oem wheels. I'd stick with the 265's unless you want to lift the truck a little more.