It really is a combination of 2 things:
1. What make/model hitch do you have?
And
2. If it tows to your liking, do you want to readjust the entire hitch or just focus on adjusting the tongue height?
From the sounds of it, you're just pursuing getting the trailer level rolling down the road. In that case, with your tongue a bit high, see if your hitch head can be adjusted down on the shank but still leave the correct ball angle. This will retain your current tension on the bars but adjust the ball down and level out the trailer.
Also, comparing the old and new truck. The diesel has a bit more front end weight (6.7 vs 6.2) and that will help minimize the affect of weight on the trailer hitch and front end lift.
Going from a F150 Ecoboost 145" wheelbase to the F250 6.2 156" wheelbase and towing the same trailer, i didn't have to adjust my hitch at all. The trailer still rode very level and even checking on the scale, the F250 was actually better balanced front to rear than the F150 was.
Bottom line, if possible, maybe just adjust the height and see how it tows then make needed adjustments from there.
And, THIS THREAD IS WORTHLESS WITHOUT PICS!!! What'st the new rig look like?
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2017 Forest River Surveyor 247BHDS...
...Tugged by a 2016 F250 XLT FX4 SuperCrew, Shortbed 6.2L, 4wd, 3.73...
...Joined with a Husky Centerline TS 800-1200lbs WDH