Fail Safe thermostat on 90 RCSB

[Mythic]

So as some of you know, I recently replaced my radiator and thermostat on my truck. I put in a Fail Safe thermostat thinking I was doing a good thing. Everything seemed good for a day or so, but then I noticed that the temp would rise almost to overheating and then drop to just over 100 degrees. And then it repeats over and over. I have read a little on the the fail safes and apparently people have had mixed experiences with them. I am going to get a regular thermostat and put it in today and hope at takes care of the issue. Have any of you experienced issues like this?

 

[trailer-trash]

My fail safe thermostat floats around alil bit too....