sales@lingenfelter.com
Lingenfelter should be able to provide you with a 160 t-stat.
phone.260.724.2552
As others have asked, what is your reason for wanting the 160?
I can tell you that if you're trying to ward off a run hot issue the t-stat alone isn't going to solve your problem.
A larger radiator will help.
Personally I'd stay away from aluminum radiators. In my continuing efforts to solve my own heating problems I've discovered that aluminum radiators are not meant to be in a daily driver. They were/are built for racing applications and are expected to be treated as a disposable commodity being replaced every couple of races.
As for what trouble will a 160 cause? Probably none other than as Mark has stated it will remain open most of the time. In your winter months you may have to let the truck run in the driveway for a bit longer until it gets up to operating temp.