1997 Dodge Ram Engine Swap

[skipcfd]

I need some help.....
I have a 97 Dodge Ram 1500, that we swapped engines from a 5.2 to a 5.9, along with the transmission. It runs good, but the coolant gauge is pegged at 260, also a check engine light is on. The local mechanic who swapped the motors said that the coolant sensor was changed, but he couldn't get the gauge to change. The coolant temperature was fine. Then, there was something with the cam sensor that he couldn't get it to reset. He mentioned that the harness is different for the different motors, and that the computer may need flashed.
Has anyone had any experience with this?
Is it worth going through with having it flashed etc.?

 

[Riccochet]

You really need the correct harnesses, engine and cab, or go through the pin out differences between the harnesses and make the proper corrections. A flash isn't going to correct your issues.