I bought a shiney new loadrite 6000 pound trailer, comes with a 14" tire. the FAQ says ball hight of 21-22 inches. Is that fully loaded or empty? Am I supposed to guess how much the back of the truck is going to go down after the trailer is on, or is there some sort of a formula? I'm thinking the tongue will probably weigh about 500 pound when the boat is on, but I dont want to run and buy a bunch of receivers just to try it out.<br /><br />Any help would be greatly appreciated, it's my first boat and first trailer and first trailer hitch. Thanks