I'd be very loath to set an incubator for Pantherophis eggs at that level. Incubating at too high temps is the most frequent cause of deformed hatchlings (kinks being the classic sign).
Setting the incubator in the 78-to-82 degree range is far safer. It may take a few days longer for the eggs to hatch, but the babies will be more robust, and there's very little chance that any will be kinked. Temps of 85 or higher are almost guaranteed to cause deformities, and if you set the incubator at 84, you don't allow any leeway for upward fluctuation.
Eggs can do well even at 76 or 77 deg., don't be impatient to get them to hatch too quickly.