I've got a quadcab Hemi 4X4 with the towing package (3.91 gear and LT rated tires). It tows my open car trailer fine, without bars.

When we moved to the UP. I bought a 24' enclosed and made the 450 mile (one way) trip from Chicago, through central Wisconsin a couple of times.

The first trip was without sway bars, and was a little shaky at times.

Adding sway bars really helped for subsequent trips.

My truck has air bags. I wouldn't try towing a heavy trailer without them, and LT rated tires are a must.