Reef, I sent you an e-mail. Like I said in the post, to run 37's like you are talking, you are going to need some very specific components to make it all work. You deviate even a little bit and you are asking for some major rubbing issues or damage to the tranny (too tall of a tire with not enough gear). Plan on spending about $4000 to do what I recommend. I did a lot of research and tons of measuring. Even then I had to do a little bit more modification than I was originally planning. Also keep in mind that this allows you to run the truck up to full twist and not have rubbing. If you are planning on just a street queen (which is not what I am getting the impression you have in mind), then you can relax what I say a little (very little) bit.
If you want to see pictures of what you are looking at, check out
http://www.fordtruckworld.com and then do some looking through the galleries for "Thermo". There, you will see my detailed explanation of how to do the wheel well mod I talked about, cutting of the fender, and what the truck looks like all twisted up and how little room that is left over under the worst case conditions.
Not trying to steer you away, but there are some members around that have tried what I did and didn't have too good of luck. hate to see you spend big money not to get what you are after.