You will never know for certain until you get a four corner weight. In lieu of that axle weights at any CAT scale, other commercial scale or even some weigh stations may get you in the ball park.
If it me and I was pretty weighted I would go to 5 p.s.i.g. below max.
Tom, Cheryl & Blossom(coonhound mix) Formerly of Bellingham,WA'05 Winnebago Journey 36G. FL-XC, Cat 350, aero muffler, AFE filter, 4 FSD Koni's, ultra track bell, SafeT+, FMCA397030, WIT 129107