Not sure if my way is technically the right way or not, but this is how I do it. First thing is the ball mount needs to be level, most weight distributing hitches I have seen have, have provisions for this. Trucks like the 3500 sit tail high, so it is very important to adjust the ball mount so it is level. On most mounts, there are washers that can be added, or removed to level out the mount, when just re-tighten the whole thing. Next I like to hook the trailer up to the truck, lock it on and adjust the tongue jack till the trailer sits level. then hold the equalizing bars, and stretch out the chains in front of their mounting locations. Make a note of which link will go on it's mount while in this position. Jack up the truck/trailer with the tongue jack till, till you can install the chains on their mounts, two links down from where they were marked when level. This usually gets me very close to where I need to be, you can adjust up or down from there as needed. This method is only for the chain mounts that are stationary, the ones that move and use a bar to tensions them are different. For those, I level the trailer as before, and hold the bars up to their mount and see where the chains are when the MOUNTS ARE IN THERE CLOSED POSITION. Then I go down one link and see how that feel, again you can adjust from there, but this should get you close. Good Luck.