This is one of our preferred vendors of fordfullsize.com They can answer all of your tuning questions and put into a tuner with custom tunes. A small discount if you mention you`re a member of FordFullSizecom a Fully Driven Automotive Network. http://5startuning.com/
I would go with 5 Star tuning and an SCT Livewire TS (it's what I have mounted on the dash) They have the standard tuners also that are a little cheaper, but don't give you the extra gauges. You can also order a tuner from them to just change the tire size and gear ratio, then order custom tunes later and have them emailed to you.
No rubbing on any bumps. As for turning. The little rubber under the bumper is the only thing it rubs. And that's on harder turns. But a little trimming and it's gone. Hope this helps you.
Do they hit toward the back? Can you add some caster to move the tire forward in the wheel well or will that make it hit up front?
No they don't hit in the back. And I'm not sure about adding caster to push them forward. Because the rubber on the lower part of the bumper is were it was rubbing at on sharp turns. No issues towards the back at all.
So are you having issues at all, or just not sure about them overall? If there isn't any rubbing, why not stick with them?
I am going with the 37's. I thought when I put them on they were to much for the truck to turn the little gears. But I wasn't that. Found out my motor was crap! Motor swapping now. Plus I have 4.88 gears for the front and back to help with performance.