Just installed some 285/60/20 Duratracs on my stock rims yesterday and they are my favorite purchase thus far! No rubbing at all at full lock with NO level, gives the truck a whole new attitude! Mileage is too soon to tell but I can say they're quiet on the highway though they do track a bit more than the stock tires but not bad at all.
Next will be a 1.5" level up front and a 2" rear block. I will start my headlight retros as well and maybe some new running boards. Truck is coming together nicely.