I would be interested to know your truck weight with out the camper to see what the Igloo is running. I have a 96 crew cab f250 diesel which I would have thought was roughly the same empty weight as yours but...
Empty I'm at 7080 and loaded with my Northstar 850 I'm 9840. Camper and stuff is 2780. Based on what the stated weights for the Igloo is (2670) plus 1000# for stuff and water the igloo should run at aprox 3700#. That should be roughly 920# more than mine but you are 2300 more.
The reason I ask is I'm looking for a Northstar hard side this winter. Real life weights when possible is better than "Well it's about".
Thanks,
Kevin