I think we can help get you sorted out. However, we need some more info.
Personally, I am not a big fan of the Reese Dual Cam because of how finicky it is. It does work well when dialed in. When it's not dialed in..well... I'll just leave it at that. I much prefer a round bar Eaz-Lift with dual sway bars...again different discussion. LOL.
Let's put first things first.
1) Your WD bars are probably undersized for the trailer. The GVWR on the trailer is 7400 lbs, your tongue weight could easily be 1000 lbs plus loaded up. Basically rendering your 800 lb bars undersized.
2) make sure your tires (all 8) are aired up to max PSI that is located on the tires sidewall.
3) tell us if you have round bar or trunnion bar style hitch
4) Tune your brake controller so it makes the trailer brakes lead the truck so you avoid a situation where the trailer is stopping slower than the truck.
5) describe the sway you feel. Sway is nearly uncontrollable, what most describe as sway is just the suck and pull motion from passing vehicles. This is 100% normal. However, the suck and pull is unsettling if you can feel the TT being sucked and then the truck bing sucked. You want the pressure on the rig to be be the same from the truck to the trailer.
6) your truck is more than capable of handling a 7400 GVWR trailer, we just got to get some things squared away.
So if you can give us some more info and provide some pics we would love to help get this straightened out.
Here is my experience with a 31.5 ft TT and a 1997 F150, I towed with a standard WD hitch without sway control. It was not set up correctly and handled terribly, very scary situation driving like this.
I adjusted the WD hitch to be correct for the truck and pull again... The rig handled so much better, bu I got significant wiggle from passing vehicles, semis,and the worst was minivans!! Wiggle is the oscillation of the trailer independent of the truck, not sway, just the feeling that the TT was wiggling around back there.
I added a single sway bar and 75% of the wiggle between the truck and the trailer was gone.
I added a second sway bar and all of the wiggle was gone. The pressure from passing vehicles and wind pushed on the truck and trailer as one unit. There was little to no wiggle anymore, just a nice comfy tow...every single time.
I read on RV.net how I was unsafe and a danger to the entire community for running friction controls so I bought dual cam...I ran them and found that they towed no better than my rig did with the two friction bars. I now run two friction bars and prefer this set up.
We can help, we just need more info from you.
Thanks!
Jeremiah