Well after reading many, many forums with no definite answers, I decided just to try and see if 35X12.50's on stock 16.5 rims would fit on my 2000 F-350 4X4 quad cab with NO lift and had BF Goodwrich All Terrains installed last week. They fit and only minorly rub at full turn against the leaf springs. I plan on adjusting my steering stops and then it will be no problem. The tires were sitting fairly close to the front bumber, so I just moved it forward about an inch and now they clear easily. I will post better pictures soon so that you guys cans see, but I think it sure helped to fill out those fenderwells. I just wanted to post this to help those like me.

 

On 99 -04's, The important area to watch, is the lower rear of the front fender.
When turning , and hitting an incline such as a steep driveway, you will get into the sheet metal.

I have pictures in my gallery of how close they are, and my truck had the X - springs and a 5.4, the tallest combo made.