And before you order that thermostat, there have been recent posts you can search for an alternate temp OEM one, I think it fits one of the diesels, people say it runs maybe 10 degrees cooler than stock. Your present one is stock, but might be on the low side. A new OEM stock one may make temps bump up a little, as most guys don't have your results. Look for "soft spring"

 

I've been looking for the posts concerning the deisel Tstat, b/c I think thats what I want. I hear it has a softer spring, and b/c my truck has run the past 13 years at a cooler temp, I want to continue that trend. I'll keep looking for the deisel tstat, and when I find it I'll report back. In the meantime, if anybody comes across the posts for that tstat, please let me know. Thanks guys.

 

Here is a 180 on e-bay. MOTORAD 439-180 Thermostat | eBay

 

That is a pretty good t/stat, but you might want to contact Justin and see if he has any of the soft spring versions of this one, they are made for 4 cylinder engines with less flow so they run cooler and flow more coolant at lower RPM's.
I have not seen any that are made for diesels that are a direct plug and play.

 

My bad - wrong reference on the diesel. I think the soft spring one is like start to open at 170, vs stock start to open at 180.

 

Mike, is that Justin @ Lucky 8?