Laredo 290 BH or 291TG towing

[Newk]

Does anyone have these models and think they are made rear end heavy?
We have a 290, towing with half ton... (I know, waiting for upgrade). It isn't too heavy according to the truck specs, based on weighing it on scale. On a 700 mile trip last week, I thought it fishtailed too much. I have 1 friction sway bar and WD hitch. It felt like it was rear end heavy. After every setup, I tried taking weight from the back and moving forward. Didn't help much...
When we returned, I weighed it again, for an hour, checking all weights, hooked, unhooked etc. I need to move another 300-400 pounds from the rear to the front based on tongue weight (to get 15%) and axle weights.
This model is built with the storage door in the back. It appears that you can't store much in there, as it's end heavy anyway. Has anyone else noticed this?