Definitely something I should look into. Would you go to a scale for this or would it be calculable using camper weight + tongue weight scale?
You can start by just looking at the door card and making some rough calculations. How much is the camper? What is your GCVWR and GVWR? Axle Weight Rating? How much does the trailer and Jeep weigh (probably around 6000 lbs, give or take). Take 10% of the trailer load and apply it to the Rear axle load.
If you are still OK...Estimate how much crap you can bring in the camper with you...Tools, Water, Spare parts, Food, etc. Don't forget that YOU count as payload, driving the truck. Those older 3/4's hit max payload pretty quick.
Just to be clear, I'm not saying you can't tow overloaded...I have a Colorado that I routinely overload...but you should know you're doing it and where the risks are.