If I was me, I might add the front axle capacity to the rear axle capacity.
If my sums are accurate, those two capacities add up to roughly 9,300#.
.
That is the maximum your vehicle can weigh.
That number includes:
* vehicle weight, plus
* fuel, souls aboard, cargo, tools...
... and any other weight on the pavement beneath your four tires.
.
If I was me, I might take my vehicle to a scales to verify the weight.
Let's say, for example, the scales say your vehicle weighs 6,000#.
.
Subtracting those hypothetical 6,000# from your Real-World 9,300# GVWR -- the capacity of your two axles -- gives you your cargo capacity of about (hypothetical) 3,300#.
.
That (made-up) ton-and-a-half+/- is the maximum your vehicle can legally and safely handle.
There is no 'grace' nor engineered 'slack' in this rating.
This is:
* the maximum your insurance will cover,
* the maximum the weigh-master will allow,
* the maximum your vehicle can handle without stressing components and increasing the likelihood of a disaster.