So motorad and/or jet performance thermostats suck!
The 180s start to open at 195-200.... that sounds like the stock 203 to me
The 160 is stuck closed!!
The only other thermostat i can find for the hemis are summit thermostats!! I guess ill give their 180 a shot.... maybe ill buy a 160 and 180 just to see how close they are to their rating