dphillips067, with what you are talking about, you can fit a 35x12.5" tire on the truck. The only clarifier that I will put on it is that you will have to run an 8" rim with 4.5" of backspacing.
The other thing that I will tell you to consider is what gear ratio you have in the truck. If you have the 3.73 gear, then you will be just fine. I ran this combo for like 6 years before I stepped up to 37" tires. The downside to this combination is that you must reprogram the computer else you will take a big hit in the mileage department (I lost 4 mpg, but gained 2 back after the reprogram) and you have to now also watch what you tow with the truck. The bigger tires are going to essentially make it as if your truck has a 3.31 rear end in it. If you look, trucks with the 3.31 rear end have a reduced towing capacity.
if you have 3.55 gears, then 35's may be a bit much. Can you run the truck with them and 35's. Sure. But, the question is how much strain you are putting on the tranny and are you willing to chance damaging the tranny, especially when you are hauling around either a lot of weight inside the truck or attempting to pull a trailer?
If you go with a slightly smaller tire, you can go with a wider rim and get more of the "flat face" look to the tire. Let me know what you are thinking. I have pushed the truck to its limits when it comes to tire sizes and small lifts. I know where each and every limiting spot is on the truck.