Not sure what RV you are running (signature update??), but I Run the Sailun's on my Voltage with triple axles, at 105 PSI. I did find both a weight and eventually a PSI rating stamped in the inside of the rim as I wondered if they could handle the higher pressure. It took a while on my back under it looking around the rims until I found it.
Based on what your weight stamp on the says, I would say you are fine running them at max PSI of 110 if desired, I run just a little less than max.
If is is an 8 Lug rim, I am sure it is rated at the higher PSI, that weight rating seems a little higher than many who run Sailun's S637's also, based on my lengthy searches online in the forums. Just make sure to use a good steel valve. I personally would not sun at 85PSI, as I understand it, the increased pressure of the tire is what allows us to carry closer to our max weights.
Gear