With full fresh water, we are at 4,300 lbs on the pin box (dry was 2,650). Our 104 gallon tank is forward of the axles under the basement unfortunately. It accounts for 850 lbs of weight, with a good share of it going to the pin box.
The generator, W/D and standard cargo alone pushed us to the maximum capability of our SRW, and water would have pushed us over. We hit our 7,000 lb axle weight first before the other specs. We went to the dually so we can carry water and extra cargo when we need to and not worry too much about it.