I'm shocked that nobody mentioned or addressed the glaringly obvious problem here... ANY heat source you are running NEEDS to be regulated. Period. I can't think of a single heat source that you can run flat out, 100% and achieve the correct temps. Everyone has been telling you the correct temperature range to shoot for. 90-92 on the hot side, 80-82 on the cool side. You can NOT run a UTH without being hooked to a thermostat. Those things will absolutely get hot enough to burn and even kill your snake. Same thing for the overhead bulbs you're running. Those wattages are high and without being controlled by a dimmer at the very least, will get too hot for a bp.
As you have apparently found, 140ish on an unregulated UTH. Then add in the heat lamp you have blaring on him too, you're probably cooking the poor snake. Definitely read the caresheet on this site. Invest in a thermostat to regulate the temperatures and you'll have a much happier and healthier bp.