Take this for what it's worth, but I contacted Lions Head Tire and Wheel and asked them the same thing, My Toy Hauler has the 16" 8 lugs rims and they informed me that they would support an 110psi tire if I made sure they had installed metal valve stems.
I have searched to no avail on the inside and outside of the rims to see if a psi statement was stamped on them and can find none.
Not sure if that helps you but that is what I found out.
2016 Vengeance 3062V
2013 Ram 3500 4x4 DRW
2015 Harley CVO Limited
2015 Harley CVO StreetGlide