Mod-Friendly Dealer around Sioux Falls?
 

Just as the title reads.... I am wondering if anyone can recommend a mod-friendly dealer within a few hundred miles of Sioux Falls, SD. Can also be in SW Minnesota or NW Iowa.

I just bought a 06 F250 6.0 Powerstroke. It's the second 6.0 that I've owned, but this one has the Ford factory 5yr/100k engine warranty and my other one did not. I'm looking to buddy up with a good mod-friendly dealership that will allow me to "play" with my truck without voiding my warranty.

TIA!

Wade