I thought boas in general liked cooler temps. 70-75 cooler side and 80-85 hot side. I am sure someone will chime in here.
Quick search to check my information.
"There is no set perfect temperature for boa constrictors, rather it is more of ranges of acceptable temperatures. A hot side of your setup should usually range from 87 to 92 degrees Fahrenheit and the cold, or unheated side, of your enclosure should not reach below 75 degrees Fahrenheit."