His sway bar bushings will be poly as Ford switched to them in about 2012.
There is also some reports coming out that the CHF is having some problems due to the Z-Brackets. The sway bar bracket bolts should be removed and given some Blue Locktite and torqued to 66 pounds.
I found the best bang for the buck for me was the addition of the auxiliary sway bar.
The addition of Sumos on all four corners of my F53 22,000 pound chassis I feel was not worth it, Maybe a 30% improvement on the in sway control.
Get your rig axles weighed and adjust your tire pressure to the manufactures spec for your weight, NOT the maximum on the sidewall. Good place to start is the placard in your MH.