Cougar 5th Wheel Rim Tire Pressure Rating

[Seven Gable]

I am looking to replace the original tires that came on my Cougar 336 BHS. While the axle rating is only 5,200 lbs. I would prefer to go with the Goodyear G614 RST, LT235/85R16, load range G, 3750 lb capacity. The original tires are ST235/80R16, load range E, (3520 lbs at 80 psi).

The Goodyear load/inflation table for RV's states the LT235/85R16 is good for the following loading: 110 psi, 3750 lbs. at 80 psi. 3042 lbs. While even at 80 psi they are greater than the axle rating I would like to run them at least 90 psi (3300 lbs, 25% factor of safety over axle) or preferably 100 psi (3550 lbs rating, at original tires)

I have 2 questions.
1. Has anyone replaced the original tires with the G614 and what air pressure do you run?
2. And secondly, does anyone know the max air pressure the original rims are good for?

Thanks