03 Ram 5.7 Hemi problems.

I just had the same problem with my 97 Ram with the 360. Almost identical to your story except mine shut off at every stop or when I left off the throttle to go around a turn. I ended up taking it to my buddies garage and this is what we eventually found. The coolant sensor was reading a different temp than the actual engine temp. It was saying overheat but engine heat was normal. Replaced the heat sensor and it is now back to normal and how it was running before the head gasket job.