SN95 stock sway bars adjustable??

The stock sway bars aren’t adjustable.

If you are a road racer / track fanatic and need to tweak your suspension to get that edge - that is who the adjustables are for: https://www.maximummotorsports.com/Adjustable-Rear-Swaybar-solid-axle-Mustang-1979-2004-P546.aspx

For the vast majority of mustang drivers upgrading to solid (non adjustable) sway bars is exactly what they need for better street driving / occasional autocross / less body roll. I have the eibach roll bars - I found them to give me minimal body roll at a good price point.