As of tomorrow, I will be the proud (I hope) owner of what seems to be a very well maintained 1999 4.0 P38. It appears to be in great shape. No rust, no dents, new tires, yada yada... But I am told that it overheats from time to time. Ran fine for the 15 minutes that I test drove it. Owner says that sometimes, it just overheats. Could the answer be as simple as replacing the thermastat? Can you just remove the thermastat and run these trucks or does that create some other issue? (We are in Florida so it is not an uncommon solution with other vehicles.)