I flushed out the sys once more and put a 180deg thermostate in her and took it for a long ride with plenty of stop go with no issues the temp ran just under where it was.. So where is the best location to add a aftermarket temp sending unit on the 3.9l?

 

There is a big plug on the intake just under the 5:00 position from the thermostat, in some versions that was a heater core line.

 

Thanks for the heads up on that port under the housing