Hotrod and Scott -
Thank you both for the valuable information.
I will get a thermostat in tomorrow before I start it,and I will test the gauge to see if it is woking. The gauge is electric so I will ground it out before I try the other option and have fluid to clean up.
The builder recommended that you run it for a short time to be sure the air is out of the system. I have never put a new radiator to a new block before so I was going off of his installation instructions. Beging a novice, I learn something new every day.
I will let you know what happens tomorrow afternoon.
Thanks again! I REALLY appreciate your advice.