[425HP409]

I finished the install of the 396 in my truck and installed a new temp sending unit. I also installed a new LMC temp gauge that has temp readings from 100-250 instead of the original gauge that reads cold and hot. The temp gauge only reads barely off of the 100 line when the engine is at operating temperature. I checked the gauge by opening end shorting the sending unit and the gauge responded correctly. Anyone have this problem with the LMC gauge? Or do I have a bad sending unit? I tested three different ones in water from cold to hot and they all read close to the same.