Alright good luck. Definitely don't let it ruin your trip, I was just pointing it out BC I know how my truck handles the trailer and the trailer is fairly big so we're going to want all the sway prevention. I would also say you got the correct size as I also have the 1200lb bars. The dealer first tried to give the 800 and then the service guy said no way at least 1000 and I stepped up tothe 1200 because my trailer has a high gross weight but a much lower dry weight.
The rear end of the truck will settle out its the front you want to return the weight to. I've read my owners manual many times and no where did I find where it says to restore a certain percentage of weight back to the front axle. But from driving with the hitch setup many weighs I waited till it felt comfortable and then got it weighed. I returned 360 lbs of 400 lbs so I would shoot to have all weight restored to the front end. Also make sure your bars are as parallel as possible and since you get them as close as possible to parallel if they are still a little off angle the l bracket so the bar rests on the l bracket flat
