Most all body on frame, has that body a uni-body
My Suburban is a uni-body on frame
The key is how strong did they design that uni-body?
That then says how strong and rigid is the frame? How big/hard/etc are the body
mounts. Ditto the frame doughnut brackets on the frame
As for uni-bodies and WD Hitch systems...ask why does CanAm have force transfer
brackets/gussets/etc from the traditional receiver to uni-body pan to other
parts of the pan?
It is called load and/or force transfer, or distribution to reduce the forces
at the traditional receivers stress points
Good that the OP understands and is only looking at the 2nd gen or older Durango
Where it is a uni-body on frame architecture