I've had great luck with a Stant Superstat.

 

9 times out of 10, it a small problem that causes us to think it something bigger. I'm sure thats what was causing your overheating issues. Glad you found your answer.

 

When I went back to Autozone the manager was apologetic and swapped the new T-stat and refunded for the old. After a few days driving around with out one, I finally got the new and correct T-stat in, and she holds right about 190. Case closed on the overheat. Lesson learned NEVER trust the part puller, double check everything yourself.

 

I sure am glad I read this thread. I've been battling an issue of my truck running hot ever since I rebuilt the engine. I've been through two radiators, two waterpumps, replaced the fan, and been through two thermostats -- all to no avail. Truck runs hot at odd times, but put a load in the bed or attached the trailer, throw in some hills, and it's blowing coolant.

So, I checked the one thermostat against the Failsafe 744 at O'Reilly Auto Parts last night, and wouldn't you know, the Failsafe is shorter! I'd almost bet lunch the thermostat currently in the truck is the same. I'll find out this weekend and report back in my thread that details my running hot issue.