Temp gauge problem in my 68

I installed factory gauges in my 68 this winter and fired up my car for the first time and the temp gauge went all the way into the red when it warmed up.The engine was definitely not over heated.Do I have the shunt resistor mixed up with the fuel?Or in wrong(I have it mounted vertically as this seems to be the correct way)I have the blue shunt in the fuel and the green in the temp.Is there a way to tell which is correct or do I have two of the same shunts?I installed a new sending unit but it lists as a 69 not that it should make a difference.Thanks Bruce