My setup is an '08 Dodge 2500, quad cab, long bed, 6.7 diesel, 6-spd manual. I haven't weighed my stock rack but with 4 llamas, I estimate 15 to 1600lb. My camp trailer is a 70's 20' so it's heavy compared to newer ones although I haven't weighed it. The water tank is in the front so that adds to the tongue weight. I don't use an equalizer hitch.
Fully loaded, the bed sags maybe 6" at the hitch and the trailer will sway a little but not much. The stock rack is high so I get quite a bit of sway, especially when all the llamas are standing up and moving around. It's not as bad when several lie down as they usually do. Also, when hunting away from gas stations, I put a 15gal barrel of fuel in a front corner of the bed where I can siphon it into the tank. I inflate the airbags with about 60lb which brings up the rear to normal height. It eliminates most of the sway from both the stock rack and the trailer.
