'98 5SFE

Has anyone ever had an experience with a faulty temp gauge sending unit? Are there "cheap" brands that might return a less than accurate reading?

I have an issue with my gauge reading about 3/4 when everything, and I mean everything, is new. The car had a blown motor and was replaced with a rebuilt 5SFE, along with rad, water pump, thermostat, etc..., and all sending units and sensors.

The wire that is plugged into the sending unit had a tear in the insulation, I taped it up, but I was wondering if it might have a resistance issue.

Also, has anyone ever installed an aftermarket electric water temp gauge in the stock sending unit location? What brand? Will I need an adaptor?

We put a laser temp gun to the bottom of the rad when it was at temp, and it read 192, but I don't trust it, plus I figure the outside of the rad tank could be 20 degrees cooler than the water inside. I would really like to put an aftermarket gauge in it to be sure.

TIA