1st of all, it is great that you got those weights.
Ordinarily, I would say that you need to distribute more weight to the front axle....that is still 100 lbs. light. But in this case, I believe you might have the best setup right where you are for these reasons:
Tightening up more on the spring bars will put more weight on the front axle, but will also transfer more weight to the trailer axles. You are already at the max back there. Apparently with the stats that you gave, you have 2 2000 lb. axles. If that is the case you are already over the axle load. When you get a chance, crawl under your camper, and see what the axle ratings are....there should be sticker on each axle. If indeed they are 2000 lbs. axles, then you definitely don't want to tighten up on the spring bars. Also, check the tire ratings....make sure the maximum ratings added up are below the 4180 axle weights.....and you are much better off if they are way below the ratings.
You have a 3/4 ton truck, which is a big plus. It is meant to carry some weight on the rear axle, without squatting much. As long as the truck is riding close to level without the headlights up in the air, it handles well, and you are not exceeding the RAWR, then you should be good to go with that.
Getting some heavy items out of the trailer and into the truck bed (up towards the cab) might be beneficial if possible.
My other thought is that 1000 lb. spring bars on a 500 lb. hitch is a bit much, but should probably work.
BTW, I started a new thread with these posts.
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Chap , DW Joy, and Fur Baby Sango
2017 F350 Lariat CCSB, SRW, 4x4, 6.7 PS
2017 Grand Design Reflection 337RLS