Re: Rim and tire sizes??
Rim size doesn't matter... the overall height of the tire is what matters. With a stock suspension (no lift) you can easily go to a 33" tire, with a 285 to (maybe) 315 width...... 315 may rub at full lock unless you increase the backspace by 1/4 to 1/2 inch.
If you don't know how to figure tire height, it's like this....
Take the section width, convert it to inches, multiply it by the aspect ratio, double that number, and add it to the wheel diameter.
As an example, a 285/70-17 should come out to about 32.7" if you do it right.
Edit..... I just noticed it's an F150..... I was referring to an F250 when I said it would take a 33" tire. I have no idea what you can put on a 150.