With front and rear heavy duty sway bars, our 2007 2350 rocks and rolls very little when parked. Of coarse, the same benefits are felt when driving.
HD sway bars are a 2-fold advantage over stock. I highly recommend them as all motor homes, regardless of brand and model, are loaded to near the max load rating of the chassis. Heavy duty sway bars are not over-kill. Actually having the stock sway bars is an severe under rated condition. All Ford E350 and E450 front sway bars are the same one used in the E150 passenger van. It just isn't doing much for a chassis loaded 6 fold. The rear bar has a similar story.
About the Ford E350/E450 OEM shocks.......they are the same used on the Ford E250 van, so how well are they suited for the task of a motor home weighing 5 times that?
The deficiencies go on and on. The steering stabilizer too. That is why I always say a mouthful when it comes to Ford suspension upgrades. We upgraded our 2007 E350 suspension in all these areas plus adding a rear trac bar. If all that prevents one accident, it paid for itself 10 fold.