If you load 2100 lbs in the trailer ahead of the axles it will likely end up being mostly in the kitchen area where most of the weight will go onto the trailer axles. A good guess would be 1400 lbs on the axles and 700 on the pin. If you put a 1000 lbs in the garage all of that weight will end up on the trailer axles plus the 150 lbs that it takes off the king pin. Real rough your loaded trailer will put an additional 550 lbs on the king pin vs empty. So the pin weight might be 3300 loaded and empty around 3450...... perfect set up.