I have that exact same year truck - an '03 FX4 and I'm running 285/70/17 BFG A/T's with absolutely ZERO issues whatsoever. No rubbing, no binding, no issues with turning radius. They've been through all types of mud, dirt, snow/ice...and when they wear out, I'll get another pair.
*they do wear down slightly faster than the stock 265/70/17's that came with the truck, but nothing major and very little noise on the highway.